To find the equation of a circle when you know the radius and centre, use the formula \({(x - a)^2} + {(y - b)^2} = {r^2}\), where \((a,b)\) represents the centre of the circle, and \(r\) is the ...

As a tangent is a straight line it is described by an equation in the form \(y - b = m(x - a)\). You need both a point and the gradient to find its equation. You are usually given the point - it's ...

Everything in physics is described by an equation. Equations can describe the shape of lines, curves, surfaces, and just about any object you can think of. In fact, you’d be hard-pressed to think of ...