QUADRATIC EQUATION - INTRODUCTION , SOLUTION OF QUADRATIC EQUATION & RELATION BETWEEN ROOTS & CO-EFFICIENTS
INTRODUCTION
The algebraic expression of the form ax2 + bx + c, a 0 is called a quadratic expression, because the highest order term
in it is of second degree. Quadratic equation means, ax2 + bx + c = 0. In general whenever one says zeroes of the
expression ax2+bx + c, it implies roots of the equation ax2 + bx + c = 0, unless specified otherwise. A quadratic
equation has exactly two roots which may be real (equal or unequal) or imaginary.
SOLUTION OF QUADRATIC EQUATION & RELATION BETWEEN ROOTS & CO-EFFICIENTS
a.
The general form of quadratic equation is ax2 + bx + c = 0, a != 0.
The roots can be found in following manner :
This expression can be directly used to find the two roots of a quadratic equation
b.
The expression
is called the discriminant of the quadratic equation.
c.
if
1.
2.
3.
d.A quadratic equation whose roots are
Example :
if are the roots of a quadratic equation
, then the equation whose roots are
Solution :
since are the roots of a quadratic equation
so
Putting
2 and 2 are the roots.
The required equation is