Question 2: What does the area difference mean in mathematics? The difference between several graphic areas
Question 3: What is the meaning of extreme value range in junior middle school mathematics? Just remember! ! ! ! ! ! ! ! ! Range is the largest and smallest number in the group. Difference and temperature difference are the same. The variance is 1/ group number ((one number-average) 2+ (another number-average) 2+ ...) Variance indicates the fluctuation of numerical value. For example, it depends on variance to reflect whether a person's grades are stable, okay?
Question 4: What does the difference method mean in mathematics? Difference method is a fast calculation method. When comparing the sizes of two fractions, this method can be used when other fast calculation methods such as "direct division" or "identity method" are difficult to solve. It is an advanced skill based on high school mathematics and applied to data analysis and rapid calculation of public examinations.
Difference method is an approximate numerical solution of differential equation. Specifically, the difference method is to replace differential with finite difference and derivative with finite difference quotient, so that the basic equation and boundary conditions (generally differential equations) are approximately expressed by difference equations (algebraic equations), and the problem of solving differential equations is transformed into the problem of solving algebraic equations. In elasticity, difference method and variational method are used to solve plane problems.
Chinese name
difference method
gender
science
kind
mathematics
Should be used
Econometric elasticity
catalogue
1 Fast calculation of data analysis
? Applicable form
? Basic definition
? Code of Conduct
? Pay special attention to
2 Econometrics
? Problem solving steps
? Mathematical thought
Data analysis and fast calculation
edit
Applicable form
When comparing two fractions, if the numerator and denominator of one fraction are only a little bigger than the other fraction, it is often difficult to compare the size relationship with "direct division" and "transformation with the same method", but the difference method can solve this problem well.
Basic definition
Among the two fractions that meet the "applicable form", we define the fraction with large numerator denominator as "big fraction" and the fraction with small numerator denominator as "small fraction", and we define the new fraction obtained by the difference between the numerator denominator of these two fractions as "difference fraction". For example, 324/53. 1 is compared with 3 13/5 1.7, where 324/53. 1 is "big score" and 313/51.
Code of Conduct
Use "small score" to compare "poor score" instead of "large score";
1, if the difference is greater than the fraction, the fraction is greater than the fraction;
2. If the difference value is less than the small value, the large value is less than the small value;
3. Difference is equal to small points, and big points are equal to small points.
For example, "11/kloc-0 instead of 324/53. 1 compare with 3 13/5 1.7" because1/kloc-0. 3 13/5 1.7 (which can be obtained simply by "direct division" or "assimilation"), so 324/53.1> 3 13/5 1.7。
Pay special attention to
First, the "difference method" itself is an "accurate algorithm" rather than an "estimation method", and the obtained size relationship is accurate rather than rough;
Second, "difference method" and "similarity method" are often used together, and "difference method after similarity method" and "difference method after similarity method" are two situations that are often encountered in data analysis and rapid calculation.
Thirdly, direct division is often needed when comparing the difference score obtained by the difference method with the small score.
Fourth, if the two scores are very close, we even need to use the "difference method" twice, which is relatively complicated, but if it is skillfully used, it can greatly simplify the calculation.
econometrics
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Difference method is a proper term in econometrics and an effective method to overcome the correlation of related sequences. It transforms the original econometric model into a difference model and then carries out OLS estimation, which is divided into first-order difference method and generalized difference method (also known as iteration method).
Problem solving steps
Steps:
First, the establishment of differential equations
Secondly, the difference scheme is constructed.
Third, solve the difference equation.
Four: accuracy analysis and inspection
Mathematical thought
By Taylor series expansion and other methods, the differential quotient of function values on grid nodes is used to discretize the derivatives in the control equation, so as to establish the equation with the values on grid nodes as unknowns. Convert differential problems into algebraic problems.
Big number, small number
Comparison between 9/5 and 7/4
(9-7)/(5-4)=2/ 1
2/ 1 is greater than 7/4, so 9/5 is greater than 7/4 ... >; & gt