Question

please help! Verify each trigonometric equation by substituting identities to match the right hand side of the equation to the left hand side of the equation. - tan2x + sec2x = 1

Answer 1

Didn't I just answer this question?

Answer 2

you didnt explain how to do it

Answer 3

Well don't delete the question and start a new one, just say so... Use this to rewrite the left side:

tan^2x = sin^2x / cos^2x
sec^2x = 1 / cos^2x

Answer 4

so it would be -sin^2x/cos^2x + 1/cos^2x =1
where do I go from here?

Answer 5

You have a common denominator!

Answer 6

so -sin^2x +1/cos^2x

Answer 7

no..

\[\frac{ -\sin^2x }{ \cos^2x } + \frac{ 1 }{ \cos^2x }\]

Common denominators means you can add them together

Answer 8

What do you mean add them together? Isn't that what I just did?

Answer 9

ohhhh you didn't put brackets you should have written

(-sin^2x +1)/cos^2x

Very different! Ok good now you can simplify the numerator using the fact that

sin^2x + cos^2x + 1

Answer 10

so am I trying to get rid of the denominator now? which would make it -sin^2x + cos^2x +1?

Answer 11

How do I finish this?

Answer 12

cool thanks for answering

Answer 13

Sorry I had to go.

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

substitute this into the fraction

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