I don't know which province you are from, so it's not good to recommend information. Besides, I should be good at math. I think math problems should be accurate, not too many, not too many formulas, and very simple. The key is to remember for understanding. This is to practice some problems, and you will know a little about mathematics. This is called mathematical thinking. The exam depends on it. Besides, math is not difficult, but troublesome. Don't be afraid. If you don't understand, you must understand. This is a set of rings. If you simply don't understand, it will be difficult to learn in the future. If you are not interested, you can't learn well naturally, so you will fall into a vicious circle. So you must be slow and steady, and you will be excellent. This is my experience in studying mathematics for more than ten years. Please share it. There are not many formulas, so you don't need to memorize them like endorsement. If you use it too much, you will remember it naturally. If I really can't do it, I will push them away. I forgot the first n items and geometric series formulas several times in the exam, and I didn't push them out as usual. The following formulas are for reference only: multiplication and factorization.

a2-b2=(a+b)(a-b)

a3+b3=(a+b)(a2-ab+b2)

a3-b3=(a-b(a2+ab+b2)

Triangle inequality

|a+b|≤|a|+|b|

|a-b|≤|a|+|b|

| a |≤b & lt； = & gt-b≤a≤b

|a-b|≥|a|-|b|

-|a|≤a≤|a|

Solution of quadratic equation in one variable

-b+√(b2-4ac)/2a

-b-√(b2-4ac)/2a

Relationship between root and coefficient

X 1+X2=-b/a

X 1*X2=c/a

Note: Vieta theorem.

discriminant

b2-4ac=0

Note: The equation has two equal real roots.

b2-4ac >0

Note: The equation has two unequal real roots.

B2-4ac & lt； 0

Note: The equation has no real root, but has a plurality of yokes.

formulas of trigonometric functions

Two-angle sum formula

sin(A+B)=sinAcosB+cosAsinB

sin(A-B)=sinAcosB-sinBcosA

cos(A+B)=cosAcosB-sinAsinB

cos(A-B)=cosAcosB+sinAsinB

tan(A+B)=(tanA+tanB)/( 1-tanA tanB)

tan(A-B)=(tanA-tanB)/( 1+tanA tanB)

ctg(A+B)=(ctgActgB- 1)/(ctg B+ctgA)

ctg(A-B)=(ctgActgB+ 1)/(ctg b-ctgA)

Double angle formula

tan2A=2tanA/( 1-tan2A)

ctg2A=(ctg2A- 1)/2ctga

cos2a = cos2a-sin2a = 2 cos2a- 1 = 1-2 sin2a

half-angle formula

sin(A/2)=√(( 1-cosA)/2)

sin(A/2)=-√(( 1-cosA)/2)

cos(A/2)=√(( 1+cosA)/2)

cos(A/2)=-√(( 1+cosA)/2)

tan(A/2)=√(( 1-cosA)/(( 1+cosA))

tan(A/2)=-√(( 1-cosA)/(( 1+cosA))

ctg(A/2)=√(( 1+cosA)/(( 1-cosA))

ctg(A/2)=-√(( 1+cosA)/(( 1-cosA))

Sum difference product

2sinAcosB=sin(A+B)+sin(A-B)

2cosAsinB=sin(A+B)-sin(A-B)

2cosAcosB=cos(A+B)-sin(A-B)

-2sinAsinB=cos(A+B)-cos(A-B)

sinA+sinB = 2 sin((A+B)/2)cos((A-B)/2

cosA+cosB = 2cos((A+B)/2)sin((A-B)/2)

tanA+tanB=sin(A+B)/cosAcosB

tanA-tanB=sin(A-B)/cosAcosB

ctgA+ctgBsin(A+B)/sinAsinB

-ctgA+ctgBsin(A+B)/sinAsinB

The sum of the first n terms of some series

1+2+3+4+5+6+7+8+9+…+n = n(n+ 1)/2

1+3+5+7+9+ 1 1+ 13+ 15+…+(2n- 1)= N2

2+4+6+8+ 10+ 12+ 14+…+(2n)= n(n+ 1)

12+22+32+42+52+62+72+82+…+N2 = n(n+ 1)(2n+ 1)/6

13+23+33+43+53+63+…n3 = N2(n+ 1)2/4

1 * 2+2 * 3+3 * 4+4 * 5+5 * 6+6 * 7+…+n(n+ 1)= n(n+ 1)(n+2)/3

sine law

a/sinA=b/sinB=c/sinC=2R

note:

In ...

rare

Represents the radius of the circumscribed circle of a triangle.

cosine theorem

B2 = a2+C2-2 acco b

Note: Angle B is the included angle between side A and side C..

the standard equation of the circle

(x-a)2+(y-b)2=r2

Note: (a, b) is the central coordinate.

Circular general equation

x2+y2+Dx+Ey+F=0

Note: D2+E2-4f > 0

Parabolic standard equation

y2=2px

y2=-2px

x2=2py

x2=-2py

Transverse area of right prism

S=c*h

Oblique prism side area

S=c'*h

Side area of regular pyramid

S= 1/2c*h '

Transverse area of regular prism

S= 1/2(c+c')h '

Yuantai lateral area

s = 1/2(c+c’)l = pi(R+R)l

Surface area of ball

S=4pi*r2

Cylindrical side area

S=c*h=2pi*h

Cone lateral area

S= 1/2*c*l=pi*r*l

Arc length formula

l=a*r

A is the radian number r of the central angle

& gt0

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 area of the straight line,

L is the length of the side.

Cylinder volume formula

V=s*h

cylinder

V=pi*r2h