A particle in a $1$D box has the wavefunction below:

$(x)=\sqrt[\phantom{2}]{\frac{2}{a}}sin(\frac{nx}{a})$

where $x$ is the location of the particle inside the box, $a$ is the length of the box, and $n$ is a quantum number $(1,2,3,...).$ Prove that this function is normalized; when evaluating the definite integral, the limits are from $0$ to $a.$