Trigonometric Identities Flashcards
1
Q
Sin(2x)
A
2sin(x)cos(x)
2
Q
Cos(2x)
A
Cos^2(x)-Sin^2(x)
{By using Sin^2(x) + Cos^2(x) = 1}
2cos^2(x) - 1
1-2sin^2x
3
Q
Tan(2x)
A
2tan(x)/1-tan^2(x)
4
Q
Sin^2x + cos^2x
A
1
5
Q
Cosec(x)
A
1/sin(x)
6
Q
Sec(x)
A
1/cos(x)
7
Q
Cot(x)
A
1/tan(x)
8
Q
1 + Tan^2(x)
A
Sec^2(x)
9
Q
1 + Cot^2(x)
A
Cosec^2(x)
