# Length of arc

1. Jun 13, 2009

### intelli

1. The problem statement, all variables and given/known data

find the length of the arc

x = 3y^ (4/3) - 3/32y^(2/3) and y lies between 0 and 216

2. Relevant equations

l = integral sqrt (1 + (dy / dx )^2)

3. The attempt at a solution

after integration i got this y + 3/16y ^(-4/3) / (-4/3)

i have to apply 0 and 216 is that correct i get a ridiculous answer

2. Jun 13, 2009

### Cyosis

You can easily check if your answer is correct or not by differentiating the primitive you've found with respect to y. If it is the correct one it should equal the integrand after differentiation. In your case this is not true, so you didn't integrate correctly.

Last edited: Jun 13, 2009