The tangent will have an equation in the form y = m x + c so to find the equation you need to find the values of m and c. First, find m, the gradient of the tangent.

A spinning hollow circle is a great way to suggest the passing of time in a PowerPoint show. Susan Harkins shows you how to make this simple animation.

First, find m, the gradient of the tangent. On a diagram, draw the circle and the tangent at the point P (3, -4) and draw the radius from the centre (0, 0) to the point P.