find the roots of the quadratic equation by factorisation and 2xsquare + x -6=0
Answers
ANSWER:
- Zeros are -2 and 3/2.
GIVEN:
- P(x) = 2x²+x-6
TO FIND:
- Roots of the above expression.
SOLUTION:
=> 2x²+x-6 = 0
=> 2x²+4x-3x -6 = 0
=> (2x²+4x)+(-3x-6) = 0
=> 2x(x+2)-3(x+2) = 0
=> (x+2)(2x-3) = 0
Either (x+2) = 0
=> x = (-2)
Either (2x-3) = 0
=> 2x = 3
=> x = 3/2
Zeros are -2 and 3/2.
NOTE:
Some important formulas:
(a+b)² = a²+b²+2ab
(a-b)² = a²+b²-2ab
(a+b)(a-b) = a²-b²
(a+b)³ = a³+b³+3ab(a+b)
(a-b)³ = a³-b³-3ab(a-b)
a³+b³ = (a+b)(a²+b²-ab)
a³-b³ = (a-b)(a²+b²+ab)
(a+b)² = (a-b)²+4ab
(a-b)² = (a+b)²-4ab
Given:
- We have been given a quadratic polynomial (2x² + x - 6 = 0).
To Find:
- We need to find the zeroes of this polynomial.
Solution:
We have been given that,
p(x) = 2x² + x - 6 = 0.
We can find the zeroes of this polynomial by the method of splitting the middle term.
We need to find two such numbers whose sum is 1 and product is -12.
Two such numbers are +4 and -3.
Substituting the values, we have
2x² + 4x - 3x - 6 = 0
=> 2x(x + 2) - 3(x +2) = 0
=> (x + 2)(2x - 3) = 0
Either (x + 2) = 0 or (2x - 3) = 0.
When (x + 2) = 0
=> x = -2
When 2x - 3 = 0
=> 2x = 3
=> x = 3/2
Hence, zeroes of this polynomial are -2 and 3/2.