\begin{align} \dfrac{1-\cos x+\sin x+\tan x}{\sin^2x+x^3} &= \dfrac{2\sin^2\frac{x}{2}+\sin x\dfrac{1+\cos x}{\cos x}}{\sin^2x+x^3} \\\ &= \dfrac{2\dfrac{\sin^2\frac{x}{2}}{x^2}+\dfrac{\sin x}{x}\dfrac{1+\cos x}{x\cos x}}{\dfrac{\sin^2x}{x^2}+x} \\\ &\to\dfrac{\dfrac12+1\times\infty}{1+0}=\infty \end{align} as $x\to0$.