Question

Please Help!! I've tried numerous times and am still getting wrong answer....thanks :)


Use left and right endpoints and the given number of rectangles to find two approximations of the area of the region between the graph of the function and the x-axis over the given interval.
g(x) = 2x^2 − x − 1, [3, 5], 4 rectangles

Answer 1

i can help , bear with me, helping other people

Answer 2

ok, thanks,i have the leftend point...but not the right end point....i don't know where i went wrong there

Answer 3

i am here, but i am helping multiple people, can you wait

Answer 4

just keep tagging me so i dont forget you

Answer 5

yes, i can

Answer 6

ok

Answer 7

ok im back

Answer 8

delta x = (b-a)/n

delta x = ( 5 - 3 ) / 4 = 1/2

Answer 9

yeah, i got that

Answer 10

so first lets look at the x axis

we have
x = 3, 3.5, 4, 4.5, 5 (note that there are 5 values here)

Answer 11

ok...i have that part and to find y you plug that into the function, correct?

Answer 12

Left endpoint sum = 1/2 * f(3) + 1/2 * f(3.5) + 1/2 * f(4) + 1/2 * f(4.5)

Right endpoint sum = 1/2 * f(3.5) + 1/2 * f(4) + 1/2 * f(4.5) +1/2 * f(5)

Answer 13

for the right, i got 63 and thats correct...but for the left i got 48.5 and thats wrong @perl

Answer 14

ok checking

Answer 15

i would also factor out 1/2

Answer 16

ok..i'll try that

Answer 17

also ill make a little table