Mathjax test 1 for plugin

For the continuous random variable with probability density function:

f(x) = \left\{ {\begin{array}{*{20}{c}}{\frac{3}{{11}}({x^2} + 2),\,\,0 \le x \le 1}\\{0\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,otherwise}\end{array}} \right.

Find correct to four decimal places (P(x \le 0.9)

\hat{H}\Psi=E\Psi