What are the math formulas for junior high school? What are the collations of all mathematical formu

The math formula for the third year of junior high school is as follows:1. Each inner angle of a regular n-sided is equal to (n-2)180° n.

2. The basic property of proportion: if a:b=c:d, then ad=bc; If ad=bc, then a:b=c:d.

3、tana＝cot（90°-a）＝cotb；cota＝tan（90°-a）＝tanb。

4. S cylindrical side: S side + S bottom = 2 RH + 2 R.

5. S circle = r.

Junior 3 Math Formula:

1. Square difference formula.

a²-b²=（a+b）（a-b）。

2. Perfect square formula.

a²+2ab+b²=（a+b）²。

3. Cube sum formula: a +b = (a + b) (a -ab + b).

4. Cubic variance formula.

a³-b³=（a-b）（a²+ab+b²）。

5. Complete cube sum formula.

a³+3a²b+3ab²+b³=（a+b）³。

6. The formula of complete cubic variance: a -3a b + 3ab -b = (a-b).

7. Three perfect square formulas: a + b + c + 2ab + 2bc + 2ac = (a + b + c).

8. The formula for the sum of the cubes of three terms: a + b + c -3abc = (a + b +) (a + b + c -ab-bc-ac).

9. The area of the rectangle = length and width.

10. The area of the square = the length of the side The length of the side.

11. The area of the triangle = the height of the base 2.

12. The area of the parallelogram = the height of the base.

13. The area of the trapezoid = (upper bottom + lower bottom) height 2.

14. The area of the circle.

Pi radius radius.

15. Solution of a quadratic equation: -b+ (b2-4ac) 2a-b-b+ (b2-4ac) 2a.

Middle School Mathematics Learning Methods:

1. Do a good job of previewing:

Read carefully during the unit preview to understand the learning content of the recent stage, read carefully during the lesson preview, pay attention to the process of knowledge formation, and make a good record of difficult concepts, formulas and rules, so as to listen to the lecture with questions.

2. Listen carefully to the class:

Listening to lectures should include three aspects: listening, thinking, and memorizing. Listen, listen to the ins and outs of knowledge formation, listen to the key points and difficulties, and listen to the solutions and requirements of example problems. First, we must be good at association, analogy and induction, and second, we must dare to question and ask questions.

Remembering refers to class notes - remembering methods, remembering doubts, remembering requirements, and remembering points of attention.

3. Solve the problem carefully

Classroom exercises are the most timely and direct feedback, and must not be missed. Don't rush to complete your homework, look at your notebook first, review what you have learned, deepen your understanding, and strengthen your memory.

4. Timely error correction

Classroom exercises, homework, and testing, after feedback, should be consulted in a timely manner, the reasons for the wrong questions should be analyzed, and the training of relevant calculations should be strengthened if necessary. If you don't understand the problem, you should ask your classmates and teachers for advice in time, and you can't leave the problem in a state of unsolved, and develop a good habit of finishing things today.

Junior 3 Math Formula:1. Square difference formula: a -b = (a + b) (a-b).

2. Perfect square formula: a +2ab+b = (a+b).

3. Cube sum formula: a +b = (a + b) (a -ab + b).

4. Cubic deviation formula: a -b = (a-b) (a + ab + b).

5. The arc length of the sector l=the central angle (radian) r= n r 180 (the central angle) (r is the radius of the fan).

6. The sector area s=n r 360=lr 2 (l is the arc length of the fan).

7. The radius of the bottom surface of the cone r=nr 360 (r is the radius of the bottom surface) (n is the central angle).

There are many mathematical formulas for junior high school, and the common ones are listed below:

1. Perimeter formula: The following types of perimeter formulas are common in junior high school:

The circumference of the rectangle (length and width) is 2, c=2(a+b).

The circumference of the square is 4, c=4a.

Circumference Diameter Pi , c=2 r.

2. Area formula: The following types of geometric area formulas are common in junior high school:

The area of the rectangle is long and wide, s=ab.

The area of the square is the length of the side and the length of the side, s=a.

Triangle area base height 2 ,s=ah 2 parallelogram area base height ,s=ah trapezoidal area (upper bottom lower bottom) height 2 ,s=1 2(a+b)h circular area radius radius pi ,s= r sector area radius radius pi center angle number (n) 360 ,s=n r 360.

3. Primary function formula: The primary function is a straight line, and the expressions are as follows.

Point oblique: y-b=k(x-a); The slope k is known as well as the crossing points (a, b).

Two-point formula: (y-b) (x-a)=(b-d) (a-c); It is known that the slope of two points (a, b) and (c, d) is (b-d) (a-c) oblique truncation: y=kx+b; It is known that the slope k,y intercept is b, that is, the crossing point (0,b) according to the point oblique formula.

Intercept formula: x a+y b=1; It is known that the intercepts of the x and y axes are a, b, that is, two points (a, 0), and (0, b) according to the two-point formula.

4. Quadratic function expression: The quadratic function is a parabola, and there are three expressions.

General formula: y=ax +bx+c; （a≠0）

Vertex formula: y=a(x-h) +k; [a≠0 fixed point (h,k)].

Intersection formula: y=a(x-x1)(x-x2); [The parabola intersects the x-axis at (x1,0)(x2,0)].

5. Quadratic function image: quadratic function expression y=ax +bx+c; Quadratic functions are axisymmetric graphs.

The quadratic term coefficient a determines the direction of the opening (a 0, the opening is upward; a 0, the opening is down).

Axis of symmetry: x = b 2a

Vertex coordinates: [ b 2a, (4ac-b) 4a ].

b²-4ac;

The number of intersections between the parabola and the x-axis (δ 0, 2 intersections; δ=0, 1 intersection; δ 0, there is no intersection).

One. The math formula for the third year of junior high school is as follows:

1. Each inner angle of a regular n-sided is equal to (n-2)180° n.

2. The basic property of proportion: if a:b=c:d, then ad=bc; If ad=bc, then a:b=c:d.

3、tana＝cot（90°-a）＝cotb；cota＝tan（90°-a）＝tanb。

4. S cylindrical side: S side + S bottom = 2 RH + 2 R.

5. S circle = r.

Two. Junior 3 Math Formula:

1. Square difference formula: a -b = (a + b) (a-b).

2. Perfect square formula: a +2ab+b = (a+b).

3. Cube sum formula: a +b = (a + b) (a -ab + b).

4. Cubic deviation formula: a -b = (a-b) (a + ab + b).

5. The perfect cubic sum formula: a +3a b + 3ab +b =(a + b).

6. The formula of complete cubic variance: a -3a b + 3ab -b = (a-b).

7. Three perfect square formulas: a + b + c + 2ab + 2bc + 2ac = (a + b + c).

8. The formula for the sum of the cubes of three terms: a + b + c -3abc = (a + b +) (a + b + c -ab-bc-ac).

9. The area of the rectangle = length and width.

10. The area of the square = the length of the side The length of the side.

11. The area of the triangle = the height of the base 2.

12. The area of the parallelogram = the height of the base.

13. The area of the trapezoid = (upper bottom + lower bottom) height 2.

14. The area of the circle = pi radius radius.

15. Solution of a quadratic equation: -b+ (b2-4ac) 2a-b-b+ (b2-4ac) 2a.

The mathematical formulas of junior high school mainly include algebra, geometry and statistics.

1. Algebraic formulas

1. The quadratic equation formula -ax +bx+c=0, where a, b, and c are real coefficients, and x is an unknown number, and the value of x can be solved directly by using the root finding formula, where the sign of the discriminant formula (b -4ac) can determine the number of roots of the equation in the range of real numbers. Congratulatory rent.

2. Factorization formula - for some polynomials, the calculation process can be simplified by factorization, such as (a+b) =a +2ab+b; a²-b²=(a+b)(a-b);A -b = (a-b) (a + ab + b ) etc.

3. Newton-Leibniz formula - when calculating the value of the integral of the function f(x) from a to b, it can be solved by the Newton-Leibniz formula: f(x)dx=[f(x)](a to b)+c, where f(x) is the original function of f(x) and c is a constant.

2. Geometric formulas

1. Trigonometric formulas - sine theorem, cosine theorem and tangent theorem are the most important auspicious formulas in the third stage of the junior high school, and they are suitable for solving various triangular problems.

2. Straight line and plane formula-slope formula, two-point formula and intercept formula are the straight line formulas that need to be learned in the third stage of junior high school, while the plane mainly uses several equations such as point formula and general formula.

3. The common formulas of circles - area formula, perimeter formula, arc length formula, tangent formula and tangent formula are the geometric formulas of circles that need to be mastered in the third stage of junior high school.

3. Statistical formulas

1. Probability formulas - classical generalizations, geometric generalizations, conditional probabilities and Bayesian theorems and other probability formulas are the contents that need to be understood in the third stage of junior high school, and have a wide range of applications in statistical learning and daily life.

2. Statistical formulas - statistical formulas such as sample mean, sample variance, standard deviation, covariance and correlation coefficient are also statistical knowledge that needs to be mastered in the third stage of junior high school.

3. In general, the mathematical formula for junior high school is an indispensable tool in the process of learning mathematics, and by strengthening the understanding and application of the formula itself, it can improve the mathematical level of students and play a huge role in future study and work.

1. The formula of a quadratic equation: the equation is: ax2 bx c 0, b2 4ac is called the root - of the judgment of the imperial manuscript formula, when greater than 0 there are two roots, it is equal to 0 with two equal real roots, and less than 0, the equation has no real roots.

2. Function formula: (1) The primary function formula y kx b, its image is a straight line; (2) The inverse proportional function formula y --k x, its image is hyperbola.

3. The formula of the quadratic residual filial piety function: y=ax2+bx+c; (a, b, c are constants, a≠0), and its image is a parabola. y is called the quadratic function of x, the three elements of the parabola: the direction of the opening of the trap, the axis of symmetry, and the vertex.