Hi,

How do I express $\displaystyle sin(\theta)$ in terms of $\displaystyle tan(\theta)$ by using the identities.

I can find most of the other(s) but this one is tricky.

It is meant to be this, but I can't see how.

$\displaystyle

\pm\frac{tan(\theta)}{\sqrt{1+tan^2(\theta)}}

$

I think you can get to it using the pythagoras identity and the ratio's alone. I think I am missing an obvious substitution.

Thanks

Craig.