Learn how to write the equation of a circle. A circle is a closed shape such that all points are equidistance (equal distance ...

Learn how to write the equation of a circle given different pieces of information. When writing the equation of a circle you ...

Find the equation of a circle with radius 3 units and centre (0, 0). The radius, \(r = 3\) and \(r^2 = 9\), so the equation of the circle is \(x^2 + y^2 = 9\). What is the radius of the circle given ...

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 ...