- #1

bubbly616

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## Homework Statement

Prove the following trigonometric identity. The question is sin^4Ө =3/8-3/8cos(2Ө)

## Homework Equations

I think I'm supposed to use the power reducing formulas for trigonometric identities which are

sin^2(u)= (1- cos(2u))/2

cos^2(u)=(1+cos(2u))/2

*Let u represent any integer/value*

## The Attempt at a Solution

To expand the equation I separated the equation into (1- cos^2Ө)(1- cos^2Ө) = 1- 2cos^2Ө + (cos^2Ө)^2. I reduced it because sin^2Ө = 1 – cos^2Ө and after this I'm confused on what the next steps are.