SOLUTION OF QUADRATIC EQUATIONS BY COMPLETING SQUARE:
·
In this method here are a few steps
to follow:
i)
First of all make the coefficient of
x2 ‘1’.
ii)
Take the constant ‘c’ to the right
hand side of the quadratic equation.
iii)
Now multiply the coefficient of ‘x’
by ‘1/2’ and then square.
iv)
Add that squared term to the both
sides of the equation.
v)
Simplify the equation as much as
possible.
vi)
Take square root of the both sides
of equation.
vii)
Simplify to possible extent and find
values of variable.
viii)
Write solution set.
Example:- Solve the equation
by completing square method.
x2
– 3x – 4 = 0
Firstly, we have to make coefficient of x2 ‘1’ which is
already ‘1’.
Now, take the constant term to the right hand side of the equation.
x2 – 3x = 4
In this step, we are to multiply coefficient of ‘x’ b by ‘1/2’.
As we know a = 1, b = -3,
c = -4
So, b x 1/2 = -3 x 1/2 = -3/2
Squaring, (-3/2)2
and then adding (-3/2)2
to the both sides of the equation.
x2
- 3x + (-3/2)2 = 4 + (-3/2)2
Here we see that on the L.H.S of the equation, a complete square is
being formed .
As we know (a – b)2 = a2 – 2ab + b2
, so by this formula, we see the above equation forming a complete square on
the left side.
Therefore, (x – 3/2)2
=
4 + 9/4
(x – 3/2)2
=
16 + 9 /4
√
(x – 3/2)2 = ± √25/4
(x – 3/2)
= ±5/2
or x = 3/2
± 5/2
Here two possibilities may arise, we take either +5/2 or -5/2
So, x = 3/2 + 5/2 or x = 3/2 – 5/2
x = 8/2 & x = 4 or x = -2/2 & x = -1\
Therefore, solution set is {-1, 4}
For understanding more comprehensively, watch
the video from start to end and full procedure of solving the Quadratic
Equations by completing square has been explained with many examples.
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of quadratic equations in Urdu/Hindi in the most easy and efficient
way. In this video you’ll learn how to solve quadratic equations by the
completing square method? You'll also learn the way to solve quadratic equations
by completing square step by step with examples in easy wording. You’ll learn
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