Parabolic chord length formula in parabola y? =2px, and the chord length formula is d = p+x1+x 2.
On the parabola y? =-2px，d=p-(x 1 +x 2)。
On parabola x? =2py, and the chord length formula is d = p+y1+y 2.
On parabola x? In =-2py, and the chord length formula is d = p-(y1+y 2).
The common formula of factorization is 1, and the square difference formula is: a? -B? =(a+b)(a-b).
2. Complete square formula: a? +2ab+b？ =(a+b)？ .
3. Cubic sum formula: A? +b？ =(a+b)(a？ -ab+b？ )。
4. Cubic difference formula: a? -B? =(a-b)(a？ +ab+b？ )。
5. Complete cubic sum formula: a? +3a？ b+3ab？ +b？ =(a+b)？ .
6. Complete cubic difference formula: a? -3a？ b+3ab？ -B? =(a-b)？ .
7. Three complete square formulas: A? +b？ +c？ +2ab+2bc+2ac=(a+b+c)？ .
8. the formula of cubic sum of three terms: a? +b？ +c？ -3abc=(a+b+c)(a？ +b？ +c？ -ab-bc-ac).
Trigonometric inequality 1, |a+b|≤|a|+|b|
2 、|a-b|≤|a|+|b|
3 、| a |≤b & lt； = & gt-b≤a≤b
4 、|a-b|≥|a|-|b|-|a|≤a≤|a|
Graphic area formula right-angle prism side area: S=c*h
Side area of oblique prism: S = c'* h
Side area of a regular pyramid: S= 1/2c*h'
Side area of prism: S = 1/2(c+c')h'
Area of frustum side: s =1/2 (c+c') l = pi (r+r) l.
Surface area of the ball: S=4pi*r2.
Area of cylinder side: s = c * h = 2pi * h
The lateral area of the cone: s =1/2 * c * l = pi * r * l.
Arc length formula: l=a*r.a is the radian number r >； of the central angle; 0
Sector area formula: s =1/2 * l * r.
Cone volume formula: V= 1/3*S*H
Cone volume formula: V= 1/3*pi*r2h.
Oblique prism volume: V=S'L Note: where s' is the straight cross-sectional area and l is the side length.
Cylinder volume formula: v = s * h；; Cylinder V=pi*r2h
Transformation formula of trigonometric function sin(-α)=-sinα.
cos(-α)=cosα
sin(π/2-α)=cosα
cos(π/2-α)=sinα
sin(π/2+α)=cosα
cos(π/2+α)=-sinα
Sine (π-α) = Sine α
cos(π-α)=-cosα
Sine (π+α) =-Sine α
tanα=sinα/cosα
tan(π/2+α)=-cotα
tan(π/2-α)=cotα
tan(π-α)=-tanα
tan(π+α)=tanα