Mathematics for Chemistry/Plotting graphs

The properties of graphsEdit

The most basic relationship between two variables   and   is a straight line, a linear relationship.

 

The variable   is the gradient and   is a constant which gives the intercept. The equations can be more complex than this including higher powers of  , such as

 

This is called a quadratic equation and it follows a shape called a parabola. High powers of   can occur giving cubic, quartic and quintic equations. In general, as the power is increased, the line mapping the variables wiggles more, often cutting the  -axis several times.

PracticeEdit

Plot   between -3 and +2 in units of 1.

Plot   between -4 and +1 in units of 1.

Plot   between -5 and +4 in units of 1.