Originally Posted by

**alleysan** Hi,

I'm stressing out because I've been on this problem for hours and I'm still getting nowhere.

The question asks:

"""

Let R denote the region that lies below the graph of $\displaystyle f(x)=2+4x^2$ on the interval [-1, 2].

Estimate the area of R using six approximating rectangles of the same width and

(a) left endpoints,

(b) right endpoints

"""

my prof doesn't really have notes on what to do and I'm really confused since it wants an estimate, and not an exact answer...

For (a), since the area of one block is:

$\displaystyle (3/n)(2+4(i(3/n))^2)$

but I'm not even sure if that's right...

Please help me! Student in distress!