(a) Use the Riemann sum definition of a definite integral to calculate the value of the integral (Ar' + 2r) dr. *Note: Cri - n n(n ( 1 ) (2n |- 1 ) 2 and Er ? = 2 6 and Er ? = n(n+ 1) 2 (b) Use the Fundamental Theorem of Calculus to check your answer to Part (a). Problem 2. Evaluate