Before we learn linear regression, we need to know the equation of a straight line. We have already learned the slope of a line.
It is given as the tangent of the angle made by a straight line with 𝑥 -axis in the anti-clockwise (or counter-clockwise) direction.
Consider the straight line shown below. Let its equation be
𝑦=𝑚𝑥+𝑐
where
𝑦 is the 𝑦 -coordinate of the point lying on the line
𝑥 is the 𝑥 -coordinate of the point lying on the line
𝑚 is the slope of the line
𝑐 is the intercept made by the line on the 𝑦 -axis
Note: The above form of the equation of a straight line is called the slope-intercept form. There are other forms as well. But for the sake of learning linear regression, we will stick to the slope-intercept form only.
