factorise 4 root 3 X square + 5 x minus 2 root 3
Answers
firstly multiply the coefficient of x² to the constant term
Here, 4√3 × 2√3 = 24
Now
we have to split 24 as to get 5 either by subtracting or by adding.
=> 4√3x² + 5x - 2√3
4√3 x² + 8x - 3x - 2√3
4x ( √3x + 2 ) - √3 ( √3x + 2 )
( 4x - √3 ) ( √3x + 2 )
Concept:
We need the concept of polynomials.
Polynomial is the form of an expression with constants as real numbers and powers of variable x.
Formula required:
Quadratic formula: -b±√b²-4ac/2a
we find the roots and write them in the factorised form:(x-α)(x-β) where α and β are the roots.
Given:
We are given a polynomial of degree 2
To find:
We are asked to factorise the given polynomial
Solution:
The polynomial is given as 4√3x²+5x-2√3
We first find the roots of the polynomial.
To find the roots we have the equation as :
4√3x²+5x-2√3=0.........................(1)
Since the polynomial is of degree 2, we will get two roots.
We use the quadratic formula to find the roots:
-b±√b²-4ac/2a where a is the co-efficient of x² and b is the co-efficient and c is the constant.
From Eqn(1): a=4√3, b=5 and c=-2√3
Let α and β be the roots
then, from the quadratic formula
=-5±√5²-4x4√3x(-2√3)/2x4√3
=-5±√25+32x3/8√3
Taking the plus and minus parts separately,
for plus part:
α=
=
=
=
=
α=
For minus part:
β=
=
=-5-11/8√3
=-16/8√3
β=-2/√3
Hence, with these roots we can write the factorised form as:
(x-3/4√3)(x+2/√3)