13. Work through the following steps to evaluate f, (x2 + 6) dx using the limit definition of the integral. a] We know that a = and b =. b) Using n subintervals, 4x = c) Write an expression for sample right end poinit xi = a + i 4x Note: your answer will be an expression in terms of i and n. d) Now find the sum of the areas of n approximationg rectangles. Note: your answer will be an expression in terms of n . (use special sum formulas to convert powers of i contained in f(x:)4x) ( f ( x ) Ax = 1=1 e) Finally, find the exact value of the integral by letting the number of rectangles approach infinity. [ (x2 + 6) dx = lim, -> Elf (x;) Ax =