Introduction to Quadratic equations

A quadratic equation is one by which the power of the unknown is ‘2’. That is, the unknown must be raised to the power of 2.

The general form of a quadratic equation is given by the relation

ax ² + bx + c = 0

Where a ≠ 0.

The reason why a must not be zero is that if ‘a’ = 0, the equation will no longer be quadratic.

This is demonstrated as follows:

ax² + bx + c = 0 and if a = 0, the we have

(0 × x²) + bx + c = 0 and this will become

0 + bx + c = 0

Therefore, we have bx + c = 0 which gives an equation with ‘x’ having a power of ‘1’

There are four methods of solving quadratic equations. These are

1.     Factorization method,

2.     Completing the squaremethod,

3.     Formula method, and

4.     Graphical method

Click to continue with discussion of the methods and solved questions.