Cosine Theorem b2=a2+c2-2accosB Note: Angle B is the included angle between side A and side C..
The standard equation of a circle (x-a)2+(y-b)2=r2 Note: (A, B) is the center coordinate.
General equation of circle x2+y2+Dx+Ey+F=0 Note: D2+E2-4f > 0
Parabolic standard equation y2 = 2 pxy 2 =-2p _ = 2 pxy 2 =-2py.
Lateral area of a straight prism S=c_ lateral area of an oblique prism S=c'_
Lateral area of a regular pyramid S= 1/2c_' lateral area of a regular prism S= 1/2(c+c')h'
The lateral area of the frustum of a cone S = 1/2(c+c')l = pi(R+R)l The surface area of the ball S=4pi_2.
Lateral area of cylinder S=c_=2pi_ lateral area of cone s = 1/2 _ = pi _ _
The arc length formula l=a_a is the radian number r > of the central angle; 0 sector area formula s= 1/2__
Conical volume formula V= 1/3__ Conical volume formula V= 1/3_i_2h
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_ cylinder V=p_2h.
Multiplication and factorization A2-B2 = (a+b) (a-b) A3+B3 = (a+b) (A2-AB+B2) A3-B3 = (A-B (A2+AB+B2))
Trigonometric inequality | A+B |≤| A |+B||||| A-B|≤| A |+B || A |≤ B < = > -b≤a≤b
|a-b|≥|a|-|b|-|a|≤a≤|a|
The solution of the unary quadratic equation -b+√(b2-4ac)/2a-b-√(b2-4ac)/2a
The relationship between root and coefficient x1+x2 =-b/ax1_ 2 = c/a note: Vieta theorem.
discriminant
B2-4ac=0 Note: This equation has two equal real roots.
B2-4ac >0 Note: The equation has two unequal real roots.
B2-4ac & lt； Note: The equation has no real root, but a complex number of the yoke.