Runge-Kutta method with y'' + 16siny = 32sin4t, y(0) = 0, y'(0) = 0, h = 0.1

[hamood]

hello

please guys i need your help

can any one tell me how to solve higher order runge kutta method

y''+16siny=32sin4t

y(0)=0 and y'(0)=0
h=0.1

and the exact solution is
y(t)=sin(4t)-4tcos(4t)

I dont know how to break y'' to first order DE

please help me ?