Trig identities Flashcards
1
Q
sin(A+B)
A
= sinAcosB + cosAsinB
2
Q
sin(A-B)
A
= sinAcosB - cosAsinB
3
Q
cos(A+B)
A
= cosAcosB - sinAsinB
4
Q
cos(A-B)
A
= cosAcosB + sinAsinB
5
Q
tan(A+B)
A
= tanA + tanB /
1 - tanAtanB
(A+B) is not = 90, 270
6
Q
tan(A-B)
A
= tanA - tanB /
1 + tanAtanB
(A-B) is not = 90, 270
7
Q
sin 2A
A
= 2sinAcosA
8
Q
cos2A
A
= cos^2 A - sin^2 A
= 1 - 2sin^2 A
= 2cos^2 A - 1
9
Q
tan2A
A
= 2tanA /
1 - tan^2 A
A is not = 45, 135
