Identities Flashcards
1
Q
cos^2(x)
A
1/2(1+cos(2x))
2
Q
sin^2(x)
A
1/2(1-cos(2x))
3
Q
cos^2(x) + sin^2(x)
A
1
4
Q
tan^2(x) + 1
A
sec^2(x)
5
Q
sinAcosB
A
1/2(sin(A-B)+sin(A+B))
6
Q
sqrt(a^2-x^2)
A
x=asinΘ
-pi/2<=Θ<=pi/2
7
Q
sqrt(a^2+x^2)
A
x=atanΘ
-pi/2<=Θ<=pi/2
8
Q
sqrt(x^2-a^2)
A
x=asecΘ
0<=Θ<pi/2
or
pi <= Θ < 3pi/2
9
Q
d/dx (arcsin(x))
A
1/sqrt(1-x^2)
10
Q
d/dx (arccos(x))
A
-1/sqrt(1-x^2)
11
Q
d/dx (arctan(x))
A
1/(1+x^2)
12
Q
Integration By Parts
A
∫f’g = fg - ∫fg’
13
Q
sin(2x)
A
2cos(x)sin(x)
14
Q
cos(2x)
A
cos^2(x) - sin^2(x)
1-2sin^2(x)
2cos^2(x) - 1
