Unknown equals to trigonometric equation of itself

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specifically I have this equation

$n_p = \frac{n_A \sin(180 - \theta)}{\sin \left(60 - \sin^{-1}\left(\frac{n_A \sin(60)}{n_p}\right)\right)}$

how do I make $n_p$ the subject of the equation knowing that $0 < n_p < 2$ and $90 < \theta < 180$

wolfram alpha could solve it for me but wasnt able to produce the steps it took. I need to write an algorithm for my experiment.

I'm doing a physics experiment on prisms and snells law and ended up with this equation but lack the math ability to carry on with my experiment. Any help is appreciated.

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The denominator is of the form $\sin(a+b) = \sin a \cos b + \cos a \sin b$

So the denominator can be expanded to:

$\sin 60 \cos(\arcsin x) - \cos 60 \sin \arcsin x$

where $x = \frac{n_A\sin 60}{n_p}$

Assuming all your angles are in degrees, $\sin 60 = \frac{\sqrt 3}{2}, \cos 60 = \frac 12$

Note that $\sin (\arcsin x) = x$ and $\cos (\arcsin x) = \sqrt{1-x^2}$.

So you can now rewrite the denominator as:

$\frac{\sqrt 3}{2} \sqrt{1-x^2} - \frac x2$

The numerator can be simplified a little by noting that $\sin(180 - \theta) = \sin \theta$, so the numerator becomes $n_A \sin \theta$

May I assume your basic algebraic skills are up to handling the rest?