4.2 Definition
Any equation of the form ax^{2}+ bx + c = 0, where a, b, c are real numbers and a ¹ 0 is called Quadratic equation in the variable x.
Solution of a quadratic equation :
The value of the variable for which the two sides of a quadratic equation becomes equal is called a solution or root of the quadratic equation.
The set of roots (solutions ) is called the solution set.
Solving a quadratic equation means finding its roots
Example
Solution :  Determine whether the values given against the quadratic equation ar roots of that equation. x^{2}  6x + 5 = 0 , x = 1, 3, 5
I) Using x = 3, L. H. S = 1  6 + 5 = 0 R. H. S.
\ For x = 1, L. H. S = R. H. S
\ x = 1 is a root.
II)
Using x = 3, L. H. S = 9  18 + 5 =  4 ¹ R. H. S
therefore, x = 3 is not a root.
III) Using x = 5, L. H. S = 25  30 + 5 = 0 = R. H. S
therefore, x = 5 is a root

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Index
4.1 Theorem
4.2 Definition
4.3 Methods of Solving Quadratic Equations
Chapter 5
