SOLUTION: Help, please!!! I am supposed to circle all expressions that are equivalent to sin 4a. options are: 4 sin a cos a 2 sin 2a cos 2a 4 sin a cos a-8 sin^3 a cos a 4 sin a cos a

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Question 1029580: Help, please!!! I am supposed to circle all expressions that are equivalent to sin 4a. options are:
4 sin a cos a
2 sin 2a cos 2a
4 sin a cos a-8 sin^3 a cos a
4 sin a cos a cos 2a
sin a cos 3a-cos a sin 3a
4 sin a cos^3 a-4 sin^3 a cos a
I know the last one is equal to 4a, but I'm not sure if this is the only one or not. Thanks for any help!

Answer by ikleyn(52797)   (Show Source): You can put this solution on YOUR website!
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Help, please!!! I am supposed to circle all expressions that are equivalent to sin 4a. options are:
A) 4 sin a cos a
B) 2 sin 2a cos 2a
C) 4 sin a cos a-8 sin^3 a cos a
D) 4 sin a cos a cos 2a
E) sin a cos 3a-cos a sin 3a
F) 4 sin a cos^3 a-4 sin^3 a cos a
I know the last one is equal to 4a, but I'm not sure if this is the only one or not. Thanks for any help!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Options B), D), F)


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