Need help simplifying expression

[quantum_enhan]

The Attempt at a Solution

I'm attempting to solve a question with a few unknowns, and I managed to get it to the following form:

tanx(1-cosx)=0.25


I just can't seem to simplify it further and thus solve.. Any ideas?

 

[ystael]

It is more helpful if you post the entire original question and your work so far; otherwise we can't tell whether you've made a mistake in the work leading up to this point, or indeed whether you're expected to find an exact or merely approximate solution.

 

[quantum_enhan]

Ok.
Find theta.
2sintheta(75)(x-1.2)=45, where x=1.2costheta

 

[quantum_enhan]

sorry, x=1.2/costheta