Question

cos^2x(1 + tan^2x)

Answer 1

what do you want to do with this problem? Solve it? or...?

Answer 2

yes please!

Answer 3

i'm having trouble with trigonometric functions

Answer 4

identities*

Answer 5

Solve cos^2x(1 + tan^2x) = 0?

Answer 6

simplify. i'm so sorry!

Answer 7

ok

Answer 8

Since tanx = sinx/cosx, we have

cos^2x(1 + tan^2x)
= cos^2(x)[1 + {sin^2(x)/cos^2(x)}]
=cos^2(x) + sin^2(x)
=1

Answer 9

thanks!

Answer 10

you're welcome

Answer 11

You can also see it like this: tan^2(x) + 1 = sec^2(x). Sec^2(x) = 1/cos^2(x), and since you're multiplying by cos^2(x), cos^2(x)/cos^2(x) = 1.