5. Consider the function f(x) = 4sin' x cos(2x). a. Find f'(x). b. Find the slope of the tangent line to f(x) at x = ". Give an exact answer, not just a decimal approximation. 6. With a yearly inflation rate of 6%, prices are described by P(t) = P. (1.06)', where Po is the price in dollars when t = 0 and t equals time in years. Suppose the cost of a year of college (tuition and room & board) is Po = $70,000. Assuming college costs increase at the 6% annual inflation rate, how fast (in dollars/year) are college costs rising when t = 4