# Differentials

• Aug 6th 2013, 09:37 PM
hacker804
Differentials
Can anyone help.Im stuck on this question.

Using differentials find $\displaystyle \frac{dy}{dx}$ when $\displaystyle \frac{y}{x}-ln(x)=ln(c)$
• Aug 6th 2013, 10:48 PM
chiro
Re: Differentials
Hey hacker804.

What exactly do you mean by differentials?

You can find the derivative by re-arranging y as a function of x (and constants) and then taking the derivative or you can use implicit differentiation and get dy/dx on LHS with other expression on RHS.
• Aug 6th 2013, 11:08 PM
hacker804
Re: Differentials
I think the differential which is defined as $\displaystyle dy=f^{'}(x)dx$
• Aug 10th 2013, 08:54 PM
ibdutt
Re: Differentials
y - x Ln (x) = x Ln (c) ; y = x Ln (x) + x Ln (c), Now differentiate w r t x we get
dy/dx = Ln (x) + 1 + Ln (c)
That is it
Quote:

Originally Posted by hacker804
Can anyone help.Im stuck on this question.

Using differentials find $\displaystyle \frac{dy}{dx}$ when $\displaystyle \frac{y}{x}-ln(x)=ln(c)$