Question

Simplify (1 − cos x)(1 + cos x).

1

cos2 x

sin2 x

tan2 x

@paki @ilikemath50 @FriedRice

Answer 1

1+cosx-cosx-cos^2x

Answer 2

1-cos^2x
1-(1-sin^2x)=sin^2x

Answer 3

@Abmon98 what are you getting at

Answer 4

@marissalovescats can you help

Answer 5

Well when you foil (1 − cos x)(1 + cos x) you get 1-sin^2x

And if you look on a trig identities sheet you'll see that

sin^2x+cos^2x=1 and you subtract cos^2x from each side which tells you that

sin^2x=1-cos^2x.

So we know the answer to this is sin^2x because when you foil (1 − cos x)(1 + cos x) you get 1-cos^2x and 1-cos^2x=sin^2x.

Answer 6

I meant you get 1-cos^2x in the first line sorry