# Thread: Hmwk Help Arc length

1. ## Hmwk Help Arc length

Find the length of the curve.
8. 3x^(3/2) from x=0 to x= 5/9

9. y = 1/6 x^3 + 1/(2x) from x=1, to x=5
17) The spring of a spring balance is 6.0 in. long when there is no weight on the balance, and it is 9.0 in. long with 8.0 lb hung from the balance. How much work is done in stretching it from 6.0 in. to a length of 14.5 in.?

Namely, please provide the general arc length equation.

3. http://http://prepcalcabc0607.blogsp...rc-length.html

I cant seem to post the formula buts its in this website for arc length. thank you in advance.

4. Originally Posted by Freemymind
Find the length of the curve.
8. 3x^(3/2) from x=0 to x= 5/9

the link you provided is broken.

one form of the arc length is:

$\displaystyle \int_{a}^{b} \sqrt{1+(f'(x))^2} \, dx$

What do you get for $\displaystyle f'(x)$? a? and b?

5. does a=0 and b= 5/9 I got the anti derivative of the function which is
(6/5) x^(5/2)

6. You need to take the first derivative before you calculate the integral. Look at the equation n0083 posted, but yes your a and b are correct.