SOLUTION: Use the product-to-sum formulas to rewrite the product as a sum or difference. sin 4theta sin 2theta

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Question 1179609: Use the product-to-sum formulas to rewrite the product as a sum or difference.
sin 4theta sin 2theta
Found 3 solutions by MathLover1, MathTherapy, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

sin%28alpha%29cos%28beta%29=%281%2F2%29%28sin%28alpha%2Bbeta%29%2Bsin%28alpha-beta%29%29...............alpha=4theta, beta=2theta

sin%284theta%29cos%282theta%29=%281%2F2%29%28sin%286theta%29%2Bsin%282theta%29%29

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Use the product-to-sum formulas to rewrite the product as a sum or difference.
sin 4theta sin 2theta
She's WRONG, so IGNORE her answer! You asked for sin (4θ) sin (2θ), but didn't get that.

Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
.

The product to sum formula, relevant to this case, is


    sin%28a%29%2Asin%28b%29+=+%281%2F2%29%2A%28cos%28a-b%29+-+cos%28a%2Bb%29%29.



In the formula, use  a= 4theta,  b= 2theta.   You will get


    sin%28a%29%2Asin%28b%29 = %281%2F2%29%2A%28cos%284theta-2theta%29+-+cos%284theta%2B2theta%29%29,

or

    sin%28a%29%2Asin%28b%29 = %281%2F2%29%2A%28cos%282theta%29+-+cos%286theta%29%29.


It is your ANSWER

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