I want to solve a trigonometric equation involving a few
sine functions, for an argument of
The equation in its simplest form is
$$-\sin(3k+\phi)+\alpha\sin(2k+\phi)+\beta\sin^2k\sin(2k+\phi)=0$$, where $\alpha$ and $\beta$ constants and $k$ is a variable (a number between $-\pi$ to $\pi$), and I want to solve it for $\phi$. I tried with
Solve[-Sin[3*k + φ] + α* Sin[2*k + φ] + β*(Sin^2)[k]* Sin[2*k + φ] == 0, φ]
I get a long output, also with an error message
Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; use Reduce for complete solution information.
How do I get a correct output? which is simplified a bit?