A rectangle has one side on the x-axis, one side on the y-axis, and a corner on the graph of y = x^2 + 1.
a) Use Linear Approximation of the area formula, A(x) = xy, to estimate the increase in the area of the rectangle if the base grows from 2 to 2.2 inches.
b) Calculate exactly the increase in the area of the rectangle as the base grows from 2 to 2.2 inches.