# Eliminate arbitrary constant

1. Jun 26, 2010

### iwan2learn

I would like to eliminate the arbitrary constant in this equation:

2. x^3-3x^2y=C

3. I tried differentiating with respect to x:
x^3-3x^2y=C
3x^2-(3x^2+6xy)=0?

This is where i dunno what I will do next. I dunno know what the result of differentiating C with respect to x. I assumed it is zero but I don't know if its right. Pls help me thanks

2. Jun 26, 2010

### Staff: Mentor

Why? What exactly is the problem you're trying to solve? Differentiating with respect to x (which you attempted below) will get rid of the constant, but so what?
When you differentiate -3x2y, you need to use the product rule. y is not a constant
Since C is a constant, its derivative is zero.