Some quadratics cannot be factorised. An alternative method to solve a quadratic equation is to complete the square. To solve an equation of the form \(x^2 + bx + c = 0\) consider the expression ...

Then test your knowledge. To calculate a square number, you times a number by itself. 3² is the same as saying 3 x 3. 3 x 3 = 9 Therefore, 9 is a square number. Or, you could say, 3 squared equals 9.