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 ...

One method of obtaining this equation is to integrate dxdy over the area of a circle. Well ... in the past to find the area under a curve on a graph (before technology gave us better methods).

Jean Kelly from Dublin's Institute of Education is here with six videos full of great advice and tips for the exam.

The top part of that image is the equation itself. The bottom part is a graph of the equation, which, as you can see, is exactly the same. To be fair, this equation cheats a little bit.

Save guides, add subjects and pick up where you left off with your BBC account. Find the equation of a circle with radius 3 units and centre (0, 0). The radius, \(r = 3\) and \(r^2 = 9\), so the ...