Trig identities Flashcards
1
Q
Sin(α + β) =
A
Sin(α)Cos(β) + Cos(α)Sin(β)
2
Q
Sin(α - β) =
A
Sin(α)Cos(β) - Cos(α)Sin(β)
3
Q
Cos(α + β) =
A
Cos(α)Cos(β) - Sin(α)Sin(β)
4
Q
Cos(α - β) =
A
Cos(α)Cos(β) + Sin(α)Sin(β)
5
Q
Tan(α + β) =
A
Tan(α) + Tan(β)/ 1 - Tan(α)Tan(β)
6
Q
Tan(α - β) =
A
Tan(α) - Tan(β)/ 1 + Tan(α)Tan(β)
7
Q
Sin(2α) =
A
2Sin(α)Cos(α)
8
Q
Cos(2α) =
A
Cos^2(α) - Sin^2(α)
2Cos^2(a) -1
1- 2sin^2(a)
9
Q
Tan(2α) =
A
2Tan(α)/1 - Tan^2(α)
10
Q
Cos^2(α) =
A
1/2 + Cos(2α)/2
11
Q
Sin^2(α) =
A
1/2 - Cos(2a)/2
12
Q
Sin(α)/Cos(α) =
A
Tan(α)
13
Q
Cos(α)/Sin(α) =
A
Cot(α)
14
Q
Cos(-α) =
A
Cos(α)
15
Q
Sec(-α) =
A
Sec(α)
16
Q
Sin(-α) =
A
-Sin(α)
17
Q
Csc(-α)
A
-Csc(α)
18
Q
Tan(-α) =
A
-Tan(α)
19
Q
Cot(-α) =
A
-Cot(α)
20
Q
Sin^2(α) + Cos^2(α) =
A
1
21
Q
Sec^2(α) - Tan^2(α) =
A
1
22
Q
Csc^2(α) - Cot^2(α) =
A
1
23
Q
sinh(x) =
A
(e^x - e^-x) / 2
24
Q
cosh(x) =
A
(e^x + e^-x) / 2
25
tanh(x) =
sinh(x) / cosh(x)
or
(e^x - e^-x) / (e^x + e^-x)
26
csch(x) =
1 / sinh(x)
or
2 / (e^x - e^-x)
27
sech(x) =
1 / cosh(x)
or
2 / (e^x + e^-x)
28
coth(x) =
1 / tanh(x)
or
(e^x + e^-x) / (e^x - e^-x)
29
cosh^2(x) -sinh^2(x) =
1
30
sinh(2x) =
2cosh(x)sinh(x)
or
(e^2x - e^-2x) / 2
31
cosh(2x) =
cosh^2(x) + sinhh^2(x)
or
(e^2x + e^-2x) / 2
32
cosh^2(x) =
(cosh(2x) + 1) / 2
33
cosh(-x) =
cosh(x)
34
sinh(-x) =
-sinh(x)
35
tanh^2(x) + sech^2(x) =
1
36
coth^2(x) - csch^2(x) =
1
