I usually have problem in plotting the equations, eg y=2ux/u-x (plotting y wrt x).
Can someone suggest a link where i can get a quick idea of how to do it? Thanks!
what you have is a rational function of the form $\displaystyle y = \frac{ax}{b-x}$ where $\displaystyle \, a,b \,$ are both constants.
vertical asymptote $\displaystyle x = b$ and horizontal asymptote $\displaystyle y = -a$.
here is a link to a series of lessons about graphing rational functions ...
Graphing Rational Functions: Introduction