How do you use Riemann sums to evaluate the area under the curve of f(x) = (e^x) − 5 on the closed interval [0,2], with n=4 rectangles using midpoints?

1 Answer
May 6, 2018

the answer
S_p=-3.67701446661601

Explanation:

The sketch of our function f(x) = (e^x) − 5

graph{e^x-5 [-16.02, 16.02, -8.01, 8.01]}

the width

width=(2-0)/4=1/2

The midpoints

(0+1/2)/2=1/4
(1/2+1)/2=3/4
(1+3/2)/2=5/4
(3/2+2)/2=7/4

now find the high
f(1/4)=-3.71597458331226
f(3/4)=-2.88299998338733
f(5/4)=-1.50965704253816
f(7/4)=0.75460267600573

The sketch of our function with midpoints

enter image source here

calculate Riemann sum

S_p=width*high

S_p=(1/2)[-3.71597458331226-2.88299998338733-1.50965704253816+0.75460267600573]

S_p=-3.67701446661601