Trigonometric Functions Identities Flashcards
1
Q
sin(A+B)
A
sinAcosB+cosAsinB
2
Q
cos(A+B)
A
cosAcosB-sinAsinB
3
Q
tan(A+B)
A
tanA+tanB / 1-tanAtanB
4
Q
sinA
Reciprocal
A
1 / cscA
5
Q
cosA
Reciprocal
A
1 / secA
6
Q
tanA
Reciprocal
A
1 / cotA
7
Q
cotA
Reciprocal
A
1 / tanA
8
Q
secA
Reciprocal
A
1 / cosA
9
Q
cscA
Reciprocal
A
1 / sinA
10
Q
sinθ
Cofunction
A
cos(90-θ)
11
Q
cosθ
Cofunction
A
sin(90-θ)
12
Q
tanθ
Cofunction
A
cot(90-θ)
13
Q
cotθ
Cofunction
A
tan(90-θ)
14
Q
secθ
Cofunction
A
csc(90-θ)
15
Q
cscθ
Cofunction
A
sec(90-θ)
16
Q
Phytagorean Identities sa trigo
A
sin²A + cos²A =1
1 + cot²A = csc²A
1 + tan²A = sec²A
17
Q
sin(A-B)
A
sinAcosB - cosAsinB
18
Q
cos(A-B)
A
cosAcosB + sinAsinB
19
Q
tan(A-B)
A
tanA - tanB / 1+tanAtanB
20
Q
sin2A
A
2sinAcosA
21
Q
cos2A
A
cos²A - sin²A
22
Q
tan2A
A
2tanA / 1-tan²A
23
Q
sin²A
A
1/2(1 - cos2A)
power of function
24
Q
cos²A
A
1/2(1 + cos2A)
Powers of functions
25
tan²A
1-cos2A / 1+cos2A
| Powers of functions
26
sin A/2
±√(1 - cosA / 2)
27
cos A/2
±√(1 + cosA / 2)
28
tan A/2
1 - cosA / sin A = sinA / 1 + cosA
29
sinA + sinB
2sin 1/2(A+B) cos 1/2(A-B)
30
cosA + cosB
2cos 1/2(A+B) cos 1/2(A-B)
31
tanA + tanB
sin(A+B) / cosAcosB
32
sinA - sinB
2cos1/2(A+B) sin1/2(A-B)
33
cosA - cosB
2sin 1/2(A+B) sin 1/2(A-B)
34
tanA - tanB
sin(A-B) / cosAcosB
35
2sinAsinB
cos(A-B) - cos(A+B)
36
2sinAcosB
sin(A+B) + sin(A-B)
37
2cosAcosB
cos(A+B) + cos(A-B)
38
tanθ
| quotient identity
sinθ / cosθ
39
cotθ
| quotient identity
cosθ / sinθ
