# Math Help - Graph Equation

1. ## Graph Equation

Lost on this one, any one provide answer please:-

P and V are related by the equation

P= nRT / V

where all the other quantities in the equation are constant.

What is the gradient of a graph in which P is plotted against 1/V?
The answer must not include brackets.

Thanks.

2. Originally Posted by stanton13
Lost on this one, any one provide answer please:-

P and V are related by the equation

P= nRT / V

where all the other quantities in the equation are constant.

What is the gradient of a graph in which P is plotted against 1/V?
The answer must not include brackets.

A line has equation $y=mx+c$ where $y, x$ are your variable quantities, $m$ is your gradient and $c$ is your y-intercept.
Your equation is in the form $p = nRT.\left(\frac{1}{v}\right) + 0$.
$p, \left(\frac{1}{v}\right)$ are your variable quantities, $0$ is your y-intercept (passing through origin) and so your gradient is nRT.