Question

Decide whether the equation is a trigonometric identity. Explain your reasoning. cos^2x(1+tan^2x)=1
So what would I do to verify first?

Answer 1

1+ tan^2 = sec^2
cos = 1/sec
done

Answer 2

So what does this mean? Is it an identity? and is that all i have to do?

Answer 3

It means you manipulate the left hand side to get the right hand side.

Answer 4

is that all?...because i wish i could say that i understand...but I dont...i have no idea how to do precalc!

Answer 5

1+ tan^2 = sec^2 ok?

Answer 6

okay...ya i get that...so would it turn into
secxtanx(1-sin^2x)=sinx ??
beacuse thats what my notes say...?

Answer 7

hence, the left hand side becomes cos^2 (sec^2) , right?

Answer 8

wouldn't it turn into sin^2x?...oh wait? left hand side? i think?

Answer 9

forget your sin
look at my guide, the left hand side becomes cos^2 (sec^2) ok?

Answer 10

okay...ya..sorry...so it turns into cos^2x(sec^2)...got it

Answer 11

and cos = 1/sec ok?

Answer 12

ok

Answer 13

that is cos^2 = 1/ sec^2 ok?

Answer 14

yea i can see how that works...i think i follow