by a straight line that forms the hypotenuse of a right angle triangle with sides of length \(x\) and \(y\). This means that, using Pythagoras’ theorem, the equation of a circle with radius \(r ...

Find the equation of the tangent to the circle \(x^2 + y^2 = 25 \) at the point (3, -4). The tangent will have an equation in the form \(y = mx + c\) so to find the equation you need to find the ...