Alpha and beta are the zeroes of kx2 4x 4 alpha2 beta2 ]= 24 then find k
Answers
Some error in your question , question is in such a way --> α and β are the zero of the Kx² + 4x + 4 , α² + β² = 24 then find k ?
Solution :- α and β are the zeros of the given polynomial Kx² + 4x + 4 = 0
so, product of zeros = αβ = constant/coefficient of x² = 4/K
sum of zeros = α + β = -coefficient of x/Coefficient of x² = -4/k
Now, α² + β² = 24
⇒(α + β)² - 2αβ = 24
⇒(-4/k)² - 2(4/k) = 24
⇒16/K² - 8/k = 24
⇒ 2 - k = 3k²
⇒3k² + k -2 = 0
⇒ 3k² + 3k - 2k - 2 = 0
⇒3k(k + 1) - 2(k +1) = 0
⇒(3k -2)(k + 1) = 0
Hence, k = 2/3 and -1
Answer:
According to the question,α and β are the zeroes of polynomial kx² + 4x + 4a
= k-b
= -4c = 4α + β = -b/a
= -4/kαβ = c/a = 4/k
Given = α² + β² = 24
(α + β)² - 2αβ = 24=
(-4/k)² - 2×4/k = 24
= 16/k² - 8/k = 24
= 16 - 8k = 24k²
= 24k² + 8k - 16 = 0
= 3k² + k - 2 = 0
= 3k² + 3k - 2k - 2 = 0
= 3k(k + 1) - 2(k + 1) = 0
= (3k - 2)(k + 1) = 0
= k = 2/3 or -1