Finding the area between curves

[FARADAY JR]

Homework Statement

sketch and find the area : y=X^3, Y=X, X>/ 0

Homework Equations

The Attempt at a Solution

I'm getting pi(1/10)
but the right answer is 4pi/21 so can anyone explain to me what am doing wrong? thankx

 

[chiro]

I figured out what you did wrong.

You need to find the volume on Y = X and Y = X^3 and subtract one from the other.

So you know A = pi * y^2.

V = (pi)Integral(0,1) y^2 dx

So for Y = X you get V = (pi) * 1/3
for Y = X^3 you get V = (pi)* 1/7

Subtract volume 2 from volume 1 you get

V_Final = (pi) (1/3 - 1/7) = (pi) 4/21.

 

[FARADAY JR]

thank you, so i found that my mistake was not setting up the problem, it was the LCD. thanks a lot.