Fourier series Problem on vibrating string with initial displacement initial velocity Problem 1

Problems on vibrating string with initial displacement and initial velocity given Solve the problem of the vibrating string for the following boundary condition: y(0,t)=0 y(l,t)=0 ∂y/∂t (x.0)=x(x-l),0 to l y(x,0)={█(x in 0 to l/2@(l-x) in l/2 to l )┤