Satx digital currency
Publish: 2021-04-19 06:09:44
1.
Digital money is legal
digital currency itself is legal in China. Digital currency is defined as Internet goods in China, but the relevant supervision is still blank, and digital currency is still in the gray area in China. Well known digital currencies include bitcoin, Leyte coin, Ruitai coin, thousand gold card, dog coin, etc
however, there are also some non developers who use the cover of digital currency to carry out pyramid schemes, such as the Vicat scheme, treasure scheme, Porter scheme and so on
development materials:
digital currency is different from the virtual currency in the virtual world, because it can be used for real goods and services transactions, not limited to online games. The early digital currency (digital gold currency) is a form of electronic currency named after the weight of gold. Today's digital currency, such as bitcoin, lightcoin and ppcoin, is an electronic currency created, issued and circulated by check sum cryptography. It is characterized by the use of P2P peer-to-peer network technology to issue, manage and circulate currency. In theory, it avoids bureaucratic examination and approval, so that everyone has the right to issue currency
2. Inverse function is the inverse function, which is to exchange the independent variable and dependent variable of a one-to-one equation, where f ^ (- 1) (x) = (x-1) ^ (1 / 3), f ^ (- 1) (4) = 3 ^ (1 / 3), which is about 1.44
3. For the math part of SAT, the inherent view of Chinese students is that this part is too simple and can get high scores without great effort. However, according to the statistics of the results of the new SAT test, only a few students can score 800 in mathematics, and few students can score 780 or above. Most of the students' mathematics scores are between 700 and 750
what causes this seemingly simple test to fail to get the highest score? Today's big questions may help you with your math
1. What is the math test
this question seems a little naive. Many students will say, "isn't mathematics the test of the four knowledge points?" Or, some students will say: "mathematics test to understand the ability of the topic." These answers are not wrong, but not comprehensive
for the mathematics part of foreign examinations, we are used to simplifying mathematics. The low performance is simply classified as "not serious, mistakes, not careful". But in fact, the mathematics part is a very comprehensive part. A high score in mathematics requires not only the understanding of mathematical knowledge, but also excellent scientific thinking and good habits. This point can be proved by analyzing the problem-solving process:
the general problem-solving process of Mathematics:
read the question - understand the meaning of the question - simplify the problem - transform it into a mathematical model - use mathematical knowledge to solve it - get the answer
almost all the questions have to go through such a process, and the lack of each step will lead to the wrong question. In addition, because the SAT math test has 80 minutes, the accuracy and stability of the test after a long time is also a problem that needs attention
take two typical cases:
a student, good grades, impact 1500 points, but always make 5 to 7 Mistakes in mathematics
the details are as follows: I like to do mental arithmetic, but I don't like to do it by hand; If you look at the topic casually, you often get it wrong; Unfamiliar concepts, lazy to analyze, like to guess by feeling; In the process of doing questions, we often shake our feet and don't care
Student B, average grade, 1400 marks, 10 to 15 mistakes in a set of math questions
the details are as follows: read the questions carefully, but although they all know the words, they still can't be transformed into mathematical problems; Calculation is often wrong, but I don't know if it is wrong; I can't simplify the math problem. I can only guess one
2. Is it really just a "mistake" or "carelessness"
"Why are you wrong?" This is a question I often ask my classmates in class, and their answers are basically:
"I'm not careful, I read the wrong number."
"I didn't understand the title and didn't know how to start."
"mistakes, brain damage."
most students like to sum up the reasons as "carelessness", "mistakes" and so on. However, few students think about the deep problems behind the mistakes
in fact, the weak links of most students are the ability to simplify problems, the ability to transform into mathematical models, the lack of some knowledge points, and the problem of problem-solving habits
1. Problem simplification and mathematical model transformation
most students who are not good at mathematics are stuck in this problem. Only understand the surface meaning of the topic, can not simplify the long topic into a few simple groups of relations, let alone into a mathematical model< 2. Lack of knowledge points
sat mathematics involves four knowledge blocks. Especially in the part of statistics and data analysis, many students will have some lack of knowledge. In addition, the quadratic function part and some knowledge points of geometry will also be forgotten
3. Habit of doing questions
I found that many students do not have good habit of doing questions. The things in science are rigorous and perfect, and they are calculus oriented. But a lot of students do the problem or not rigorous, very casual; Or just want to not count, hoping to come up with the answer
thirdly, habit and mathematical thinking are the key points.
the author puts these problems down to habit and mathematical thinking
first of all, in the process of preparing for the exam, students must improve their writing habits. On the one hand, the words "not serious" and "mistake" can't explain the reason. All the "not serious" and "mistakes" are the performance of the bad habit of doing questions in science. Therefore, do not simply use "mistakes" to explain wrong questions, but need to carefully think about each step of the process of doing questions, and graally develop a rigorous habit of doing questions
on the other hand, overcome the habit of thinking only, not counting. Most of the students who come back from America will have this problem. They do math, they don't use scratch paper, they don't calculate, they want to see the answer directly. This is a big taboo in solving mathematical problems. The reason why the students who take part in the Chinese college entrance examination have a strong mathematical ability is that they calculate the questions repeatedly, so that practice makes perfect. Specifically speaking, the best way is to translate and extract the mathematical relations mentioned in each sentence of the title. When all the questions are read out, all the mathematical relations are also transformed, and then solve the problem, it will be directly simple. In addition, the process must be more hands-on calculus< Moreover, we should pay attention to cultivate our own mathematical thinking. Many students can not simplify the application problem, the most essential problem is the lack of mathematical thinking. Mathematical thinking is not equivalent to mathematical knowledge points, but the re application of mathematical knowledge points to development. Good mathematical thinking can not only help you solve simple problems accurately, but also help you analyze and dece new knowledge when you encounter unfamiliar problems< 4. The dimension of preparing for the exam
October is coming. In preparing for the exam, we suggest students to do the following things:
1. Do four sets of og real questions and may and October real questions carefully
the so-called "doing well" refers to reviewing the whole thinking process from reading the questions to getting the answers after completing the questions, and thinking about their own good and wrong places. Analyze the causes of errors, add unfamiliar knowledge points, and sort out the wrong questions. In addition, there are inferences, to be able to contact different sets of questions in the common test point
2. Do some difficult simulation problems properly
the math part doesn't have to worry about whether the thinking is consistent with the official. Appropriate to do some rare simulation problems, can be very good training thinking< Since the SAT reform, many students have exclaimed that mathematics is actually about English reading. In fact, the long question stem does bring some challenges to most Chinese candidates, especially when they encounter some different expressions at home and abroad, such as:
in a circle with center O, central angle AOB has a measure of 5 π/ 4 radians. Thearea of the sector formed by central angle AOB is what fraction of thearea of the circle?
the area of the sector formed by central angle AOB is what fraction of the area of the circle? Can the students understand that the fraction here is actually the meaning of ratio, which means that the answer is also a fraction (proportion). Obviously, one of the background knowledge behind this problem is that the circumference of a circle is 2 π， So the title means 5 π/ 4 and 2 π 5 / 8. Because I don't understand that fraction is actually ratio, many students don't know how to do it. For this kind of unfamiliar problems and problem stems, students need to be patient to clear up the difficulties one by one. So the real topic of og is a very effective material to sweep away the difficulties< In addition to the threshold brought by the English expression itself, the inconsistent expression of some mathematical symbols also confused the students to a certain extent. The best example is in multiple functions, where students see that it may not immediately correspond to f (g (x)). In this way, it has caused obstacles to the examination. Another example is the expression f (x, y) = 2x + Y-3, whether students can convert to y = - 2x + 3.
what causes this seemingly simple test to fail to get the highest score? Today's big questions may help you with your math
1. What is the math test
this question seems a little naive. Many students will say, "isn't mathematics the test of the four knowledge points?" Or, some students will say: "mathematics test to understand the ability of the topic." These answers are not wrong, but not comprehensive
for the mathematics part of foreign examinations, we are used to simplifying mathematics. The low performance is simply classified as "not serious, mistakes, not careful". But in fact, the mathematics part is a very comprehensive part. A high score in mathematics requires not only the understanding of mathematical knowledge, but also excellent scientific thinking and good habits. This point can be proved by analyzing the problem-solving process:
the general problem-solving process of Mathematics:
read the question - understand the meaning of the question - simplify the problem - transform it into a mathematical model - use mathematical knowledge to solve it - get the answer
almost all the questions have to go through such a process, and the lack of each step will lead to the wrong question. In addition, because the SAT math test has 80 minutes, the accuracy and stability of the test after a long time is also a problem that needs attention
take two typical cases:
a student, good grades, impact 1500 points, but always make 5 to 7 Mistakes in mathematics
the details are as follows: I like to do mental arithmetic, but I don't like to do it by hand; If you look at the topic casually, you often get it wrong; Unfamiliar concepts, lazy to analyze, like to guess by feeling; In the process of doing questions, we often shake our feet and don't care
Student B, average grade, 1400 marks, 10 to 15 mistakes in a set of math questions
the details are as follows: read the questions carefully, but although they all know the words, they still can't be transformed into mathematical problems; Calculation is often wrong, but I don't know if it is wrong; I can't simplify the math problem. I can only guess one
2. Is it really just a "mistake" or "carelessness"
"Why are you wrong?" This is a question I often ask my classmates in class, and their answers are basically:
"I'm not careful, I read the wrong number."
"I didn't understand the title and didn't know how to start."
"mistakes, brain damage."
most students like to sum up the reasons as "carelessness", "mistakes" and so on. However, few students think about the deep problems behind the mistakes
in fact, the weak links of most students are the ability to simplify problems, the ability to transform into mathematical models, the lack of some knowledge points, and the problem of problem-solving habits
1. Problem simplification and mathematical model transformation
most students who are not good at mathematics are stuck in this problem. Only understand the surface meaning of the topic, can not simplify the long topic into a few simple groups of relations, let alone into a mathematical model< 2. Lack of knowledge points
sat mathematics involves four knowledge blocks. Especially in the part of statistics and data analysis, many students will have some lack of knowledge. In addition, the quadratic function part and some knowledge points of geometry will also be forgotten
3. Habit of doing questions
I found that many students do not have good habit of doing questions. The things in science are rigorous and perfect, and they are calculus oriented. But a lot of students do the problem or not rigorous, very casual; Or just want to not count, hoping to come up with the answer
thirdly, habit and mathematical thinking are the key points.
the author puts these problems down to habit and mathematical thinking
first of all, in the process of preparing for the exam, students must improve their writing habits. On the one hand, the words "not serious" and "mistake" can't explain the reason. All the "not serious" and "mistakes" are the performance of the bad habit of doing questions in science. Therefore, do not simply use "mistakes" to explain wrong questions, but need to carefully think about each step of the process of doing questions, and graally develop a rigorous habit of doing questions
on the other hand, overcome the habit of thinking only, not counting. Most of the students who come back from America will have this problem. They do math, they don't use scratch paper, they don't calculate, they want to see the answer directly. This is a big taboo in solving mathematical problems. The reason why the students who take part in the Chinese college entrance examination have a strong mathematical ability is that they calculate the questions repeatedly, so that practice makes perfect. Specifically speaking, the best way is to translate and extract the mathematical relations mentioned in each sentence of the title. When all the questions are read out, all the mathematical relations are also transformed, and then solve the problem, it will be directly simple. In addition, the process must be more hands-on calculus< Moreover, we should pay attention to cultivate our own mathematical thinking. Many students can not simplify the application problem, the most essential problem is the lack of mathematical thinking. Mathematical thinking is not equivalent to mathematical knowledge points, but the re application of mathematical knowledge points to development. Good mathematical thinking can not only help you solve simple problems accurately, but also help you analyze and dece new knowledge when you encounter unfamiliar problems< 4. The dimension of preparing for the exam
October is coming. In preparing for the exam, we suggest students to do the following things:
1. Do four sets of og real questions and may and October real questions carefully
the so-called "doing well" refers to reviewing the whole thinking process from reading the questions to getting the answers after completing the questions, and thinking about their own good and wrong places. Analyze the causes of errors, add unfamiliar knowledge points, and sort out the wrong questions. In addition, there are inferences, to be able to contact different sets of questions in the common test point
2. Do some difficult simulation problems properly
the math part doesn't have to worry about whether the thinking is consistent with the official. Appropriate to do some rare simulation problems, can be very good training thinking< Since the SAT reform, many students have exclaimed that mathematics is actually about English reading. In fact, the long question stem does bring some challenges to most Chinese candidates, especially when they encounter some different expressions at home and abroad, such as:
in a circle with center O, central angle AOB has a measure of 5 π/ 4 radians. Thearea of the sector formed by central angle AOB is what fraction of thearea of the circle?
the area of the sector formed by central angle AOB is what fraction of the area of the circle? Can the students understand that the fraction here is actually the meaning of ratio, which means that the answer is also a fraction (proportion). Obviously, one of the background knowledge behind this problem is that the circumference of a circle is 2 π， So the title means 5 π/ 4 and 2 π 5 / 8. Because I don't understand that fraction is actually ratio, many students don't know how to do it. For this kind of unfamiliar problems and problem stems, students need to be patient to clear up the difficulties one by one. So the real topic of og is a very effective material to sweep away the difficulties< In addition to the threshold brought by the English expression itself, the inconsistent expression of some mathematical symbols also confused the students to a certain extent. The best example is in multiple functions, where students see that it may not immediately correspond to f (g (x)). In this way, it has caused obstacles to the examination. Another example is the expression f (x, y) = 2x + Y-3, whether students can convert to y = - 2x + 3.
4. There are two parts of SAT, one is SAT1 and the other is SAT2. Relatively speaking, SAT1 is relatively simple, but SAT2 will be more difficult. You may see SAT1.
5. Basic mathematical concept 1:
arithmetic mean; Weighted average; Geometric mean; Exponent, power; Base is the base of power; Cube number, cube; Square root< Basic mathematical concept 2:
cube root; Common logarithm; Digital; Constant constant; Variable variable; Inverse function; Complementary function; Linear; linear; Factorization factorization; Absolute value
I believe that many students have done a lot of SAT math exercises in the process of preparing for the exam. Through these questions, you can understand the key sat math vocabulary< Relevant coordinates:
coordinate system; Rectangular coordinate system; Origin origin; Abscissa abscissa; Coordinate ordinate; Number line; Quadrant; Slope; Complex plane< On algebraic expressions, equations and inequalities 1:
algebraic term; Like terms, similar terms; Numerical coefficient; Letter coefficient; Inequality inequality; Triangle inequality< On algebra, equation and inequality 2:
range range; Original equation; Equivalent equation is the same solution equation; Linear equation (E.g.5 x + 6 = 22)< On number theory 1:
natural number; Positive number; Negative number; Odd integer, odd number; Even integer, even number; Integer, whole number; Positive whole number; Negative whole number negative integer< On number theory 2:
continuous number; Real number, rational number, real number; Irrationality (number); Inverse countdown; Composite number; Prime number prime number; Reciprocal of reciprocal; Common divisor common divisor; Multiple times< On number theory 3:
(least) common multiple Factor (prime) factor; Common factor; Ordinaryscale, decimal scale; Nonnegative; nonnegative; Ten tens; Units; Mode; Median number; Common ratio
all triangles:
equilateral triangle; Scalene triangle; Isosceles triangle; Right triangle; Oblique oblique triangle; Inscribed triangle
other planar figures:
arc; Line, straight line; Line segment; Parallel lines; Segment of a circle arc
about stereo graphics:
cube, cube number; Rectangular solid cuboid; Regular solid / regular polyhedron; Circular cylinder; Cone cone; Sphere; Solid solid
about the appendage on the graph 1:
altitude high; Depth; Side length; Circumference, perimeter; Radian; Surface area; Volume; Arm is a right triangle; Cross section; Center of a circle; Chord; Radius
the second appendage on the figure:
angle bisector angle bisector; Diagonal; Diameter; Edge edge; Face of a solid; Hypotenuse bevel; Included side clip; The right side of the triangle; The middle of a triangle; Base edge, base number
about appendage 3 on graph:
opposite side of opposite triangle; Midpoint; Endpoint endpoint; Vertex (plural forms of vertices); Tangent; tangent; Transverse section; Intercept;
arithmetic mean; Weighted average; Geometric mean; Exponent, power; Base is the base of power; Cube number, cube; Square root< Basic mathematical concept 2:
cube root; Common logarithm; Digital; Constant constant; Variable variable; Inverse function; Complementary function; Linear; linear; Factorization factorization; Absolute value
I believe that many students have done a lot of SAT math exercises in the process of preparing for the exam. Through these questions, you can understand the key sat math vocabulary< Relevant coordinates:
coordinate system; Rectangular coordinate system; Origin origin; Abscissa abscissa; Coordinate ordinate; Number line; Quadrant; Slope; Complex plane< On algebraic expressions, equations and inequalities 1:
algebraic term; Like terms, similar terms; Numerical coefficient; Letter coefficient; Inequality inequality; Triangle inequality< On algebra, equation and inequality 2:
range range; Original equation; Equivalent equation is the same solution equation; Linear equation (E.g.5 x + 6 = 22)< On number theory 1:
natural number; Positive number; Negative number; Odd integer, odd number; Even integer, even number; Integer, whole number; Positive whole number; Negative whole number negative integer< On number theory 2:
continuous number; Real number, rational number, real number; Irrationality (number); Inverse countdown; Composite number; Prime number prime number; Reciprocal of reciprocal; Common divisor common divisor; Multiple times< On number theory 3:
(least) common multiple Factor (prime) factor; Common factor; Ordinaryscale, decimal scale; Nonnegative; nonnegative; Ten tens; Units; Mode; Median number; Common ratio
all triangles:
equilateral triangle; Scalene triangle; Isosceles triangle; Right triangle; Oblique oblique triangle; Inscribed triangle
other planar figures:
arc; Line, straight line; Line segment; Parallel lines; Segment of a circle arc
about stereo graphics:
cube, cube number; Rectangular solid cuboid; Regular solid / regular polyhedron; Circular cylinder; Cone cone; Sphere; Solid solid
about the appendage on the graph 1:
altitude high; Depth; Side length; Circumference, perimeter; Radian; Surface area; Volume; Arm is a right triangle; Cross section; Center of a circle; Chord; Radius
the second appendage on the figure:
angle bisector angle bisector; Diagonal; Diameter; Edge edge; Face of a solid; Hypotenuse bevel; Included side clip; The right side of the triangle; The middle of a triangle; Base edge, base number
about appendage 3 on graph:
opposite side of opposite triangle; Midpoint; Endpoint endpoint; Vertex (plural forms of vertices); Tangent; tangent; Transverse section; Intercept;
6. Translation while doing, can help you how much is how much, after all, with two disciplines, can not be guaranteed
1. If points x and y are two different points on the same coordinate plane, which of the following may have multiple values
a circumference of circle with diameter XY (diameter, radius, perimeter, unique solution)
b area of square with diagonal length XY (diagonal, side, area, unique solution)
C circumference of isosceles triangle with XY (as long as the bottom edge is greater than the sum of two waists, indefinite, indefinite, indefinite perimeter, Multiple possible solutions)
d the area of the circle with chord length XY (the line segment between any two points of the circle is chord, uncertain, multiple possible solutions)
e the area of the equilateral triangle with chord length XY (equilateral △, side length determined, all determined, unique solution)
I think it's OK to choose C
d I doubt my understanding of English
2 The median of five different positive integers is 12. Which of the following is the most unlikely sum of the five positive integers
if you say the answer is 11, that's no problem. They are all positive integers. It's impossible that the sum is smaller than one of them
1 + 2 + 12 + 13 + 14 = 42 is the sum of all the numbers in the integer (10 ^ 100 - 38)
9 + 9... (100-2 = 98 9S) + 6 + 2 = 98 * 9 + 6 + 2 = 890
6 and 2 are two numbers
4, 5 ^ 2 and 3 ^ 3 are n × 2^ 5 × 6^ 2 × 7 ^ 3, n is a positive integer. What is the minimum possible value of N
there is 6 ^ 2 in the formula, that is, there is already 3 ^ 2, and there is one less
in addition, there is no 5
in the formula, so the minimum n is 5 ^ 2 * 3 = 75
the head is bigger, I hope it can help you
1. If points x and y are two different points on the same coordinate plane, which of the following may have multiple values
a circumference of circle with diameter XY (diameter, radius, perimeter, unique solution)
b area of square with diagonal length XY (diagonal, side, area, unique solution)
C circumference of isosceles triangle with XY (as long as the bottom edge is greater than the sum of two waists, indefinite, indefinite, indefinite perimeter, Multiple possible solutions)
d the area of the circle with chord length XY (the line segment between any two points of the circle is chord, uncertain, multiple possible solutions)
e the area of the equilateral triangle with chord length XY (equilateral △, side length determined, all determined, unique solution)
I think it's OK to choose C
d I doubt my understanding of English
2 The median of five different positive integers is 12. Which of the following is the most unlikely sum of the five positive integers
if you say the answer is 11, that's no problem. They are all positive integers. It's impossible that the sum is smaller than one of them
1 + 2 + 12 + 13 + 14 = 42 is the sum of all the numbers in the integer (10 ^ 100 - 38)
9 + 9... (100-2 = 98 9S) + 6 + 2 = 98 * 9 + 6 + 2 = 890
6 and 2 are two numbers
4, 5 ^ 2 and 3 ^ 3 are n × 2^ 5 × 6^ 2 × 7 ^ 3, n is a positive integer. What is the minimum possible value of N
there is 6 ^ 2 in the formula, that is, there is already 3 ^ 2, and there is one less
in addition, there is no 5
in the formula, so the minimum n is 5 ^ 2 * 3 = 75
the head is bigger, I hope it can help you
7. (1) 5 full arrangement = 5= 120
(2) C at the end = 4= 24 (C is placed at the end, so there are only four permutations)
that is, by mutually exclusive events, C is not at the end = 120-24 = 96 (kinds)
in fact, when C appears in the first four positions, there are 24 kinds in each position,
all are 96 kinds.
(2) C at the end = 4= 24 (C is placed at the end, so there are only four permutations)
that is, by mutually exclusive events, C is not at the end = 120-24 = 96 (kinds)
in fact, when C appears in the first four positions, there are 24 kinds in each position,
all are 96 kinds.
8. If you want someone to answer, you need to change a clear picture of the question, or just type it up
how to answer the questions?
how to answer the questions?
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