Use the tangent line found in part (b) to write down a linear approximation for
f(3+h) for small
h. Hence calculate the approximate value of
f(3.4) given by this approximation, and show that the true value of
f(3.4) is less than this approximation. Justify why the approximation always overestimates
f(x) near
x=3.
[3 marks]