# trig proofs

#### runner940

I am having difficulty getting past the first step of solving this problem, can someone help me or check this for me? Thank you (Nod)

Original Problem: sin(x)^2 - sin(x)^4 = cos(x)^2 - cos(x)^4

#### Prove It

MHF Helper
I am having difficulty getting past the first step of solving this problem, can someone help me or check this for me? Thank you (Nod)

Original Problem: sin(x)^2 - sin(x)^4 = cos(x)^2 - cos(x)^4
$$\displaystyle \sin^2{x} - \sin^4{x} = \sin^2{x}(1 - \sin^2{x})$$

$$\displaystyle = \sin^2{x}\cos^2{x}$$

$$\displaystyle = (1 - \cos^2{x})\cos^2{x}$$

$$\displaystyle = \cos^2{x} - \cos^4{x}$$.