double angle identities Flashcards
1
Q
sin 2A =
A
2 sin A cos A
2
Q
tan 2A =
A
2 tan A / 1-tan^2 A
3
Q
(#1) cos 2A =
A
cos ^2 A - sin ^2 A
4
Q
(#2) cos 2A =
A
1-2 sin^2 A
5
Q
(#3) cos 2A =
A
2 cos^2 A -1
