1, basic formula:

sin 15 =cos75 =(√6-√2)/4

sin30 =cos60= 1/2

sin45 =cos45 =√2/2

sin60=cos30 =√3/2

sin90 =cos0 = 1

tan 0 = 0 tan 30 =√3/3 tan 45 = 1 tan 60 =√3

2. Two angles and formulas:

sin(A+B)=sinAcosB+cosAsinB

sin(A-B)=sinAcosB-cosAsinB

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)

3. Double angle formula:

sin2A=2sinAcosA

cos2A=cos？ Sin. A=2cos？ A- 1= 1-2sin？ A

tan2A=2tanA/( 1-tan？ answer

4, the same angle trigonometric function:

tanA=sinA/cosA

tanA×cotA= 1

secA= 1/cosA

cscA= 1/sinA

1/cos？ A = 1+ tan? A

Sin? A+cos？ A= 1

5. Special formula:

Sin? A=( 1-cos2A)/2

Because? A=( 1+cos2A)/2

6、sin(-A)=？ -Sina

tan(-A)=？ -Tana

cos(-A)=？ Kosa