# Power law equation help

1. Feb 10, 2016

1. The problem statement, all variables and given/known data
need to solve for v? I also know the value of x=0.02

2. Relevant equations
v(x)= 47.8 ⋅ (0.451/x)^(5.39)

3. The attempt at a solution
how do I take the log of both sides, is that the right approach to solve for v?

2. Feb 10, 2016

### RUber

Apply the product rule then the power rule.

3. Feb 10, 2016

### RUber

But, if you already know x, you don't have anything to solve. Just put .02 in for x and evaluate.

4. Feb 10, 2016

I am little confused, my calculus skills stayed in first year. Do put 0.02 in the x term on the left side of the equation also, and just solve for V?

5. Feb 10, 2016

### Fredrik

Staff Emeritus
You didn't state the problem accurately, but if it's asking you to determine v(0.02), then all you have to do is to replace the x on the right by 0.02 and perform the computations. To "solve for v" would be to find an equivalent equation with v alone on one side, but the equation is already of that form, so what you need to do to solve for v is nothing at all.

That would be a good approach if you wanted to solve for x.