Y = 5xe−x, y = 0, x = 3; about the y-axis

(a) Set up an integral for the volume V of the solid obtained by rotating the region bounded by the given curve about the specified axis.
(b) Use your calculator to evaluate the integral correct to five decimal places.

Using the shell method, the volume is

Integrate by parts, taking

Integrate by parts again, with

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15