A set of two variables are related non linearly can be converted to a linear equation. The line of best fit can be written in the form

where

$$Y-{y}_{1}=m(X-{x}_{1})$$

Y=mX+cY=mX+c

where

*X*and*Y*are in terms of*x*and/or*y**m*is the gradient,*c*is the*Y*-intercept

*Recall: To find equation of straight line*

**(1)**Equation of a straight line if gradient (

*m*) and one points $({x}_{1},{y}_{1})$ are given:

$$Y-{y}_{1}=m(X-{x}_{1})$$

**(2)**Equation of a straight line if gradient (

*m*) and y-intercept (

*c*) are given:

$$Y=mX+c$$