Question

Riemann Sum: midpoint
-9x^2-5y
m=n=2
[0,2]x[0,4]

Answer 1

so the points would be
(1/2, 1)
(3/2, 1)
(1/2, 3)
(3/2, 3)

Answer 2

right?

Answer 3

area = 2

Answer 4

2 * ( -(29/4) -(101/4) -(69/4) -(141/4) )

Answer 5

= -170
but it's area so it would be 170

Answer 6

just want to make sure that's right cuz i did the lower left hand and got 76 but it was wrong

Answer 7

lower left would be (0,0) (0,2) (1,0) (1,2)
-10 * 2 -10 * 2 -19 * 2
answer 76?

Answer 8

I don't follow your question whatsoever. The equation is \(-9x^2-5y=0\)? What are \(m,n\)? What's \(\left[0,2\right]\times\left[0,4\right]\)?

Answer 9

it's a reimann sum for double integral (-9 x^2 - 5y)
m the how many squares for the x axis
n is how many squares to segment the y axis

Answer 10

[0,2] = \[0 \le x \le2\]

Answer 11

[0,4] =
\[0 \le y \le 4\]

Answer 12

cross product giving you the height

Answer 13

Gotcha.

Answer 14

here's a pic of the original problem

Answer 15

hrm

Answer 16

looks right...i get an exact answer of -176 so for midpoint you are on right track

Answer 17

ah k hopefully it takes! :0

Answer 18

here goes

Answer 19

it would be positive right?

Answer 20

oh yeah i guess if we are assuming positive volume

Answer 21

er 176 didn't work

Answer 22

and 76 didn't work for left hand

Answer 23

oh sorry thats the exact answer, you were corroct with 170 as midpoint estimate

Answer 24

correct*

Answer 25

whew had 3 chances, last chance worked
-170 was the answer

Answer 26

do you mind double checking my lower left hand answer? :)

Answer 27

pretty sure it is -76
done it about 4 times

Answer 28

yes i get -76 as well :)