# I need serious help with this problem, it's about area and distance

## Homework Statement

by reading values from the given graph of f, use five rectangles to find a lower estimate and an upper estimate for the area under the given graph of from x=0 to x=10. in each case sketch the rectangles that you use.

## The Attempt at a Solution

since their are there are 5 rectangles, the width was 2 for each of them

and when i tried to figure out the lower and upper estimate i did this

L5= 2*O^2+ 2*2^2 ..... 2 * 8^2 =128

and the answer in the back of the book is 40

and for Right end= 2*2^2 ..... 2*10^2= 440

i already did sketched the rectangle thing, and it doesn't tell me what type of graph it is, it just tells me y= f(x)

Dick
Homework Helper
The area of a rectangle is length*width. There is no 'square' in the formula.

ok, so then i dont have to square them,

i was looking at an example that was squaring them, no wonder, thanks man, i didn't think about the y= f(X)

ok so what do i do then

i didnt square the left end points and i got 40
but i did the same for the right end and i got 60

Dick
Homework Helper
You must be able to determine the values of f(0), f(2) etc from your graph. Those are the heights. The widths are all 2.

how do i do that, what formula do i use

Dick
Homework Helper
If you are going to get a numerical answer like 52 then you must be able to find f(0) etc. It's the y value of the graph when x=0 etc.

i did it, i multiplied 2 * the hieght, for every one

Dick