{change~in~x} =\frac{4}{2}= 2\). The gradient of the tangent is the negative reciprocal of the gradient of the radius. This means that the gradient of the tangent, \(m = - \frac{1}{2}\).

All lines and curves that slope downwards have a negative gradient ... are any two points on the tangent to the curve. The following graph shows the car journey from Chelsea’s house to her ...