Hey all, I've completely stuck on this one trig identity problem, I hope someone can help!

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

I've figured that the left side should probably be:

tanx - 1

= sinx/cosx - 1/1

= sinx-cosx/cosx

But I can't get the other side to that point.

Thanks in advance!

does this identity help?

\Large \frac {sin(x)}{cos(x)} = tan(x)

Try doing your problem from right to left, that is, try making

\frac{(sin^2x - cos^2x)}{(sinxcosx + cos^2x)}

into

tanx-1