Let f(t)=t2+1 for all real t. Define the function
G(x)=∫0sinxf(t)dt
for x in the interval [−2π,2π].
(a) Calculate G′(x).
(b) Evaluate G′(6π).
(c) Determine the equation of the tangent line to the graph of y=G(x) at x=6π. Express your answer in point–slope form.