Question Number 1375 by 123456 last updated on 26/Jul/15
$$\mathrm{lets}\:{f}:\mathbb{R}\rightarrow\mathbb{R}\:\mathrm{and}\:{g}:\mathbb{R}\rightarrow\mathbb{R}\:\mathrm{two}\:\mathrm{continuous}\:\mathrm{and}\:\mathrm{differentiable}\:\mathrm{functions} \\ $$$$\mathrm{suppose}\:\mathrm{that}\:{g}\left(\mathrm{0}\right)=\mathrm{0},\:\mathrm{then}\:\mathrm{compute} \\ $$$${h}\left({x}\right)=\underset{\Delta{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\frac{{g}\left({f}\left({x}+\Delta{x}\right)−{f}\left({x}\right)\right)}{\Delta{x}} \\ $$