1. a. Consider the annuity of 3800 RO per year at the end of every year for (M+D) years. If the discount rate is equal to (R+7) %, find the present value of annuity at the end of (M+D) years? b. Define Compound interest. (8 marks) (2 marks) 2. Use the definition of derivative to find derivative of f(x) = (R-4)x+(M + 2)x². (10 marks)