algebra precalculus - Using a calculating utility’s numeric solver to solve $100 = 2a sinh (frac{45}{a})$

I've tried to use the numerical calculator (Sagemath) but can't get the right formulas.

So I tried to solve it manually using $\sinh (x)=\frac{e^x-e^{-x}}{2}$, but couldn't nut it out there.

I strongly suspect that I'm missing something obvious, so any help gratefully received.

[The answer for a is $a ≈ 56.01$ BTW]

Answer

If you're looking for a reference, I'd highly recommend Wolfram Alpha. You can just type in "100 = 2a*sinh(45/a)" and get an answer, both in terms of specific functions AND numerically.

https://www.wolframalpha.com/