8. a) (4 pts) Given that A = Pe" where the amount A = $20,000 and the original; principal P =$8,000. The yearly interest rate r compounded continuously is 6.9%. How long in years f (accurate to 2 decimal places) is required to achieve the desired result for A? b) (6 pts) y= f(x) =e" has a shape similar to the standard normal curve. Find the critical point and use the first derivative test to determine whether the critical point is a relative max or relative min. Also graph the curve y = /(x)=e"* and label the coordinates of the critical point. c) (5 pts) y = /(x)= In 3+2x Find the derivative of this expression using the properties of logarithms. The LCD is required