Question

Write the expression in terms of cosθ, then simplify?

Answer 1

\[\cos^4θ - \sin^4θ + \sin^2θ \]

Answer 2

I would appreciate any and all help on this ><

Answer 3

\[\sin^2x=1-\cos^2x\]hence,\[\cos^4x-(1-\cos^2x)^2+(1-\cos^2x)\]\[\cos^4x-(1-2\cos^2x+\cos^4x)+(1-\cos^2x)\]\[\cos^4x-1+2\cos^2x-\cos^4x+(1-\cos^2x)\]\[\cos^4x-1+2\cos^2x-\cos^4x+1-\cos^2x\]\[\cos^4x+2\cos^2x-\cos^4x-\cos^2x\]\[2\cos^2x-\cos^2x\]\[\cos^2x\]