This is LaTeX code:

[latex]
f(x) = (x + \frac{x^3}{3!} + \frac{x^5}{5!} + \ldots)(x + \frac{x^2}{2!} + \frac{x^3}{3!} + \ldots)^4 = \sinh x (e^x - 1)^4
[/latex]