Trig Identities Flashcards
1
Q
tan(x)
A
sin(x)/cos(x)
and 1/cot(x)
2
Q
cot(x)
A
cos(x)/sin(x)
3
Q
csc(x)
A
1/sin(x)
4
Q
sin(x)
A
1/csc(x)
5
Q
sec(x)
A
1/cos(x)
6
Q
cos(x)
A
1/sec(x)
7
Q
cot(x)
A
1/tan(x)
8
Q
sin^2(x)+cos^2(x)
A
1
9
Q
tan^2(x)+1
A
sec^2(x)
10
Q
1+cot^2(x)
A
csc^2(x)
11
Q
sin(-x)
A
-sin(x)
12
Q
cos(-x)
A
cos(x)
13
Q
tan(-x)
A
-tan(x)
14
Q
sin(2x)
A
2sin(x)cos(x)
15
Q
cos(2x)
A
cos^2(x)-sin^2(x)
2cos^2(x)-1
1-2sin^2(x)
16
Q
tan(2x)
A
2tan(x)/1-tan^2(x)
17
Q
sin(x/2)
A
+-√1-cos(x)/2
18
Q
cos(x/2)
A
+-√1+cos(x)/2
19
Q
tan(x/2)
A
+-√1-cos(x)/1+cos(x)
20
Q
sin(x+-y)
A
sin(x)cos(y)+cos(x)sin(y)
21
Q
cos(x+-y)
A
cos(x)cos(y)-+sin(x)sin(y)
22
Q
tan(x+-y)
A
tan(x)+-tan(y)/1-+tan(x)tan(y)
