The following will introduce the necessary formula of mathematics in the senior high school entrance examination from three aspects: geometry, algebra and statistics.
1, geometric formula:
Pythagorean theorem: the square of the hypotenuse of a right triangle is equal to the sum of the squares of two right angles, that is, a? +b？ =c？ .
Area formula: the area of a triangle is equal to the base multiplied by half the height, that is, S=( 1/2)× base× height.
The formula of circumference and area of a circle: the circumference of a circle is equal to the diameter multiplied by π, that is, c = π d; The area of a circle is equal to the square of the radius times π, that is, S=πr? .
2. Algebraic formula:
Quadratic formula: quadratic formula √a×√b=√(ab).
Percentage formula: the percentage x% can be expressed in decimal form as x/ 100.
Average formula: if the average value of n numbers is a, the sum of these n numbers is equal to nA.
3. Statistical formula:
Median concept: after a set of data is arranged from small to large, the middle number is the median.
Percentile concept: after a group of data is arranged from small to large, the p th percentile means that this position contains the previous p% data.
Expand knowledge:
Trapezoidal area formula: Trapezoidal area is equal to upper bottom surface plus lower bottom surface multiplied by half height, that is, S= (upper bottom surface+lower bottom surface) × height ×( 1/2).
Binomial expansion formula: (a+b)? =a？ +2ab+b？ ; (ab)？ =a？ 2ab+b？ .
Sine theorem: In any triangle ABC, the ratio of the sine of the side length to the corresponding angle is equal, that is, a/sinA=b/sinB=c/sinC.
Summary: The formulas needed for the senior high school entrance examination are geometry, algebra and statistics. Students should master these formulas skillfully and use them correctly according to the requirements of the questions. In addition to the required formula, there are other knowledge points related to mathematics that students need to study and master in depth in order to achieve better results in the exam.