If you aren't dealing with algebra, such as x2+3x+21, then completing the square wont be able to solve the porblem, however if you are using algebra, and you cannot factorise, then completing the square will always work
Chat with our AI personalities
It cannot be solved because the discriminant of the quadratic equation is less than zero
A single equation such as the one in the question cannot be solved.
Expression: x^2 -x -12 Completing the square: (x -0.5)^2 -12.25
Completing the square is one method for solving a quadratic equation. A quadratic equation can also be solved by several methods including factoring, graphing, using the square roots or the quadratic formula. Completing the square will always work when solving quadratic equations and is a good tool to have. Solving a quadratic equation by completing the square is used in a lot of word problems.I want you to follow the related link that explains the concept of completing the square clearly and gives some examples. that video is from brightstorm.
It comes from completing the square of a general quadratic. Many people believe Brahmagupta first solved this in 628 AD.