TeX source:

\mathrm{f}_{\mathrm{y}}(\mathrm{x})= \begin{cases}\frac{2(x-L)}{(H-L)(M-L)} & \text { if } L \leq x < M \\ \frac{2(H-x)}{(H-L)(H-M)} & \text { if } M \leq x \leq H\end{cases}