Question

Question #f6f93

Answer 1

Proof below

Explanation:

`8sin^2xcos^2x=2*2sinxcosx*2sinxcosx`
First rule you'll need to know: `2sinAcosA=sin2A`
`=2*sin2x*sin2x`
`=2*sin^2(2x)`
`=1-1+2*sin^2(2x)`
`=1-(1-2sin^2(2x))`
Second rule you'll need to know: `1-2sin^2A=cos2A`
`=1-cos4x`