if h(x)=sinπ/x then find hderivative(4)

The way you typed it, sinπ would just be a constant, and

h ' (x) = -sinπ/x^2

I will guess that you meant
h(x) = sin (π/x), which would be a totally different function

h '(x) = cos(π/x) ( -π/x^2)
so h ' (4) = (-π/16)cos(π/4)

I will let you do the button-pushing.