Trig Identities Flashcards
0
Q
Half angle identities:
Cos x/2
A
+/- the square root of 1+ cosx/ 2
1
Q
Half angle identity :
Sin x/2
A
+/- the square root of 1-cosx/ 2
2
Q
Half angle identity:
Tan x/2
A
1-cosx/sinx = sinx/1+cosx
3
Q
Double angle identities:
Sin 2x
A
2sinxcosx
4
Q
Double angle identities:
Cos 2x
A
Cos^2x - sin^2x
2cos^2x-1
1- 2sin^2x
5
Q
Double angle identities:
Tan 2x
A
2tanx/ 1-tan^2x
6
Q
Pythagorean identities
Sin^2x
A
1- cos^2x
7
Q
Pythagorean identities:
Cos^2x
A
1- sin^2x
8
Q
Pythagorean identities
Sec^2x
A
1 + tan^2x
9
Q
Pythagorean identities:
Csc^2x=
A
1 + cot^2x
10
Q
Sum or difference identities:
Cos(u + v)
A
Cosucosv - sinusinv
11
Q
Sum or difference:
Cos (u - v)
A
Cosucosv + sinusinv
12
Q
Sum or difference:
Sin (u + v)
A
Sinucosv + cosusinv
13
Q
Sum or difference
Sin (u - v)
A
Sinucosv - cosusinv
14
Q
Sum or difference
Tan (u + v)
A
Tanu + tanv / 1- tanutanv
