Trigonometric Identities Flashcards
1
Q
sin^2(x) + cos^2(x) =
A
1
2
Q
1 + tan^2(x) =
A
sec^2(x)
3
Q
1 + cot^2(x) =
A
csc^2(x)
4
Q
sin(-x) =
A
-sin(x)
5
Q
csc(-x) =
A
-tan(x)
[or -csc(x)tan(-x)]
6
Q
cot(-x) =
A
cos(x)
[or -cot(x)cos(-x)]
7
Q
sec(-x) =
A
sec(x)
8
Q
sin(2u) =
A
2sin(u)cos(u)
9
Q
cos(2u) =
A
cos^2(u) - sin^2(u)
[or 2cos^2(u) - 1; 1 - 2sin^2(u)]
10
Q
tan(2u) =
A
(2tan(u)) / (1 - tan^2(u))
11
Q
sin(u) =
A
opp/hyp
12
Q
cos(u) =
A
adj/hyp
13
Q
tan(u) =
A
opp/adj
14
Q
csc(u) =
A
hyp/opp
14
Q
sec(u) =
A
hyp/adj
15
Q
cot(u) =
A
adj/opp
16
Q
sin(x) =
A
1 / csc(x)
17
Q
cos(x) =
A
1 / sec(x)
18
Q
tan(x) =
A
sin(x) / cos(x)
19
Q
sec(x) =
A
1 / cos(x)
20
Q
csc(x) =
A
1 / sin(x)
21
Q
cot(x) =
A
cos(x) / sin(x)
