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Avenged7x
 9 months ago
Prove: sin θ  sin θ•cos2 θ = sin3 θ. You must show all work.
Avenged7x
 9 months ago
Prove: sin θ  sin θ•cos2 θ = sin3 θ. You must show all work.

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Avenged7x
 9 months ago
Best ResponseYou've already chosen the best response.0idk even where to begin

myininaya
 9 months ago
Best ResponseYou've already chosen the best response.1Just thought Maybe you can take the right hand side and show the left hand side Try to play with this thought: sin(3x) is sin(2x+x)

myininaya
 9 months ago
Best ResponseYou've already chosen the best response.1That should be a hint to use the sum identity for sin

Idealist10
 9 months ago
Best ResponseYou've already chosen the best response.0Memorize the identities for cos 2*theta

myininaya
 9 months ago
Best ResponseYou've already chosen the best response.1Though I could be wrong but I don't think this is an identity.

myininaya
 9 months ago
Best ResponseYou've already chosen the best response.1One way to find out is to find a counterexample

myininaya
 9 months ago
Best ResponseYou've already chosen the best response.1try theta=pi/2 does not work

Idealist10
 9 months ago
Best ResponseYou've already chosen the best response.0sin(2x)=2*sin(x)*cos(x)

Idealist10
 9 months ago
Best ResponseYou've already chosen the best response.0cos(2x)=2cos^2 (x)1

myininaya
 9 months ago
Best ResponseYou've already chosen the best response.1Maybe the problem has been written incorrectly.

myininaya
 9 months ago
Best ResponseYou've already chosen the best response.1Unless the instructions say to: Prove if true and give a counterexample if false. If so then I have accidentally given you the answer.

Idealist10
 9 months ago
Best ResponseYou've already chosen the best response.0cos(2x)=12sin^2 (x) so what's sin(x)*cos(2x)?
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