The point slope form equation is a way to write the equation of a line when you know the slope of the line and the coordinates of one point on the line. You express a point slope form equation as ...

The tangent is perpendicular to the radius which joins the centre of the circle to the point P. As the tangent is a straight line, the equation of the tangent will be of the form \(y = mx + c\).

The straight line through two points will have an equation in the form \(y = mx + c\). Then, we can find the value of \(c\), the \(y\)-intercept, by substituting the coordinates of one point into ...