Question

if alpha and beta are two zeroes of quadratic polynomial x^2-kx+15 such that (alpha+beta)^2-2alpha×beta=34.find k​

Answer 1

Answer:

the ans is +2 or -2

i hope you understand

if you have any other doubt you can ask

Answer 2

Answer:

± 8

Step-by-step explanation:

Polynomials written in form of x^2 - Sx + P represent S as sum of their roots and P as product of their roots.

Here, if α and β are roots:

    α + β = k

    αβ = 15

In question:

⇒ ( α + β )^2 - 2αβ = 34

 Substituting value from above:

⇒ ( k )^2 - 2( 15 ) = 34

⇒ k^2 - 30 = 34

⇒ k^2 = 34 + 30

⇒ k^2 = 64

⇒ k = ±√64 = ±8

Hence the required values of k are 8 and - 8

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