0
$\begingroup$

Here is the problem I'm working on:

Estimate the area under the graph of f(x)=4x^3+6

from x=−1 to x=3, first using 4 approximating rectangles and right endpoints, and then improving your estimate using 8 approximating rectangles and right endpoints.

4 Rectangles =   168

8 Rectangles =   

(B) Repeat part (A) using left endpoints. 

4 Rectangles =   56

8 Rectangles =   

(C) Repeat part (A) using midpoints. 

4 Rectangles =   100

8 Rectangles = 

Now I got the three values in there already correct, but the other three I can't figure out what to do. This is how I worked it:

enter image description here

Ive spent at least an hour on this one problem. Thanks!

$\endgroup$
0
$\begingroup$

Why estimate when you could get an exact answer?

$$\int_{-1}^{3}4x^3+6 dx=[x^4+6x]_{-1}^{3}=-5+99=94$$

$\endgroup$
  • $\begingroup$ I wish it worked but unfortunately it didn't. $\endgroup$ – mur7ay Oct 2 '15 at 23:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.