Using your solution to Exercise 7.14, compare the derivative of the spline found in splint with the derivative of the function interpolated, z(x) = −2x(1 + x2)−2. Suppose we integrate a cubic spline...

Using your solution to Exercise 7.14, compare the derivative of the spline found in splint with the derivative of the function interpolated, z(x) = −2x(1 + x2)−2.

Suppose we integrate a cubic spline interpolant from x1 to xn. What is the value in terms of zs and xs?