Question

simplify:(cos^4x-sin^4x)/(cos^2x-sin^2x)

Answer 1

I would factor the numerator by difference of squares rule and cancel.

Answer 2

ive been trying to change sin^2x into 1+cos^2x

Answer 3

I think sin^2x=1-cos^2x

Answer 4

But I think factoring is easier.

Answer 5

so (cosx)(cosx)-(sinx)(sinX)

Answer 6

I would factor the numerator
(cos^2x)^2-(sin^2x)^2=(cos^2x-sin^2x)(cos^2x+sin^2x)

Answer 7

I was woring on it and im confused I think the answer is 2 cos^2x-1 but im not sure

Answer 8

That's not what I get. Do you see what I did in my last comment?

Answer 9

yes im sry absolutely suck at this im trying

Answer 10

You'll get better if you keep trying. :)

Answer 11

Once you factor the numerator you have a common term in the numerator and denominator. Do you see it?

Answer 12

yess

Answer 13

Once you cancel, you are left with only cos^2x+sin^2x which is the pythagorean identity.

Answer 14

So, it simplifies to 1 :)

Answer 15

thaks I have 33 problems to do by 8 am and I only have 13 done :(

Answer 16

Oh no! Let me know if you have more questions or if you get stuck.

Answer 17

I'll do my best to help :)

Answer 18

thank you