# Homework Help: Inverse Variation

1. Aug 17, 2010

### amanda_

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

If y varies inversely as the square of x, and y = 1/8 when x = 1, find y when x = 5.

y = 8/25
y = 1/200

3. The attempt at a solution
The equation to find this is y=k/x, I know that. I've tried to plug in both given answers to see which ones matched but neither of them did. I'm not sure what to plug in for k or x. I just need someone to correctly set this up for me and I'll be able to solve it.

2. Aug 17, 2010

### Staff: Mentor

No, it says that y varies inversely as the square of x.

3. Aug 17, 2010

### rock.freak667

3. The attempt at a solution
The equation to find this is y=k/x[/QUOTE]

You'll need to try again, if the cube of x is x3, the square of x is?

4. Aug 17, 2010

### amanda_

x2

So if I square 5 and cross multiply it's 8/25. Is that right?

Last edited: Aug 17, 2010
5. Aug 17, 2010

### Staff: Mentor

No, it's not. You skipped some steps. First, what is the equation? And you know that when x = 1, y = 1/8.