Solving a Quadratic Equation by Completing the Square Method
In deriving the formula for the roots of a quadratic equation we used completing the squares method. The same technique can be applied in solving any given quadratic equation through the following steps
Step 1 Write the quadratic equation in general form ax2 + bx +c = 0 .
Step 2 Divide both sides of the equation by the coefficient of x2 if it is not 1.
Step 3 Shift the constant term to the right hand side.
Step 4 Add the square of one-half of the coefficient of x to both sides.
Step 5 Write the left hand side as a square and simplify the right hand side.
Step 6 Take the square root on both sides and solve for x.
Solve x2 − 3x − 2 = 0
x2 − 3x − 2 = 0
x2 - 3x = 2 (Shifting the Constant to RHS)
Solve 2x 2 − x −1 = 0
Solution 2x2 − x −1 = 0