Let q be the function given by q(x) = (x^3)/8 + the integral of f'(t) dt from 2 to infinity. And let P(x) be the second-degree Taylor polynomial for q about x=4.(a) Find P(x) and use it to approximate q(4.2).(b) Use the Lagrange error bound to show that |q(4.2) - P(4.2)|