calculs

1) For the function f(x) = x2 + 3, find a formula for the upper sum obtained by dividing the interval [0, 3] into n equal subintervals. Then take the limit as n→∞ to calculate the area under the curve over [0, 3] 

2) For the function f(x) = 36 - x2 , find a formula for the Riemann sum obtained by dividing the interval [0,6] into n equal sub intervals and using the right-hand endpoint for each Ck. Then take a limit of these sums as n-->infinity to calculate area under the curve

3)Use finite approximations to estimate the area under the graph of the function f(x) = 25 - x^2