Thursday, November 7, 2013

High School Math Solutions – Quadratic Equations Calculator, Part 2

Solving quadratics by factorizing (link to previous post) usually works just fine.  But what if the quadratic equation can’t be factored, you're going to need a different strategy to help you solve it.

An equation in which one side is a perfect square trinomial can be easily solved by taking the square root of each side.  Easy is good, so we basically want to force the quadratic equation into the form (x+a)²=x²+2ax+a².

All it takes is making sure that the coefficient of the highest power (x²) is one.  Move the constant term to the right hand side.  Take half of the coefficient of the middle term(x), square it, and add that value to both sides of the equation.  Factor the perfect square trinomial.  Take the square root of each side and solve.

With practice you will get the hang of it.

Let’s see how it works (click here):

Here’s another example (click here):

Until next time,


  1. I wasn't familiar with the fist technique. and I did encounter this while using SymboLab, and I was confused at first.
    Maybe you should attach a little link to explain the technique on the solution? something like little question mark for those who would like a further explanation.

  2. Hi there, thank you for your comment.
    We will definitely take this into consideration.