Trigonometric identities Flashcards
1
Q
sin
A
opposite/hypotenuse
2
Q
cos
A
adjacent/ hypothenuse
3
Q
tan
A
sin/cos = opposite/ adjacent
4
Q
sec
A
1/cos
5
Q
csc
A
1/sin
6
Q
cot
A
1/tan = cos/sin
7
Q
cos^2 x
A
1 - sin^2 x or (1+cos2x)/2
8
Q
sec^2 x
A
1 + tan^2 x
9
Q
sinA*cosB
A
1/2(sin(A - B) + sin(A + B))
10
Q
sinA*sinB
A
1/2(cos(A-B) - cos(A+B))
11
Q
cosA*cosB
A
1/2(cos(A-B)+cos(A+B))
12
Q
Sin^2 x
A
(1-cos2x)/2
13
Q
Cos2x
A
Cos^2x - sin^2x or 2cos^2x-1 or 1-2sin^2x
14
Q
Csc^2x
A
1+cot^2x
15
Q
Sin(-x)
A
-sin(x)
