Quantitative Aptitude - Quadratic Equation - Formula & Concept Tutorial
An equation of the form ax2 + bx + c = 0, where a, b and c are real values and a ≠ 0, is called a quadratic equation in variable 'x'.
Here a, b, c are constants.
And x are the variable.
Let root of this quadratic equation is α and β
Therefore α + β = and αβ =
x =
- If b2 – 4ac = 0 or Discriminant D = 0 , then root are real and equal .
- If b2 – 4ac > 0 or Discriminant D > 0 , then root are real and unequal .
- If b2 – 4ac < 0 or Discriminant D < 0 , then root are imaginary and unequal .
For example –
- 5x2 + 3x + 2 = 0
Using Normal method
Here a = 5, b = 3, c = 2
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5x2 + 5x – 2x + 2 = 0
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5x ( x - 1 ) – 2 ( x – 1 ) = 0
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( 5x – 2 ) ( x – 1 )
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x = 2/5 , x = 1
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