αβ are zeros of x²-7x+9 then α-β is
Answers
GIVEN,
THESE ARE ZEROES OF ²–7+9
Given:
α and β are the zeroes of the polynomial x²-7x+9.
To Find:
The value of α-β is?
Solution:
The given problem can be solved using the concepts of quadratic equations.
1. Consider a quadratic equation ax² + b x + c = 0, let the roots of the quadratic equation be p and q. Then,
- Sum of the roots = p + q = (-b/a)
- Product of the roots = p x q = (c/a)
2. Using the above formulae the value of α-β can be calculated.
=> Sum of the roots = α + β = -(-7) = 7,
=> Product of the roots = αxβ = (9/1) = 9,
3. The value α-β can be also written as,
=> (α-β)² = α² + β² + 2αβ - 4αβ,
=> (α-β)² = (α + β)² - 4αβ,
=> (α-β) = √((α + β)² - 4αβ), (Consider as equation 1)
4. Substitute the values of α + β and αβ in equation 1,
=> (α-β) = √[(7)² - 4(9)],
=> (α-β) = √(49-36),
=> (α-β) = √(13).
Therefore, the value of α-β is √(13).