CBSE BOARD X, asked by drjamalannadka, 1 year ago

If alpha and beta are zeroes of polynomial f(x)=x2-x-k such that alpha -beta =9 , find k

Answers

Answered by kurokiri67
101
here's your answer
hope it helps
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Answered by HappiestWriter012
76
Hey there!

given α , β are zeroes of the polynomial f ( x).

Also, f ( x ) = x² - x - k.

We know that for a Quadratic polynomial, Sum of roots = - ( Coefficient of x) : Coefficient of x²

So,

α + β = - ( - 1) / 1 = 1

Also,

 \mathbf{\alpha-\beta=9} , from the question.

Solving the both equations, You would get

 \boxed {α = 5 , β = - 4.}

Now,

We know that,

Product of roots = 5 × - 4 = - 20

But, According to the given equation, Product of roots = - k.

Equating both of them,

-k = - 20

\boxed{\boxed{k = 20}} \: \:

Therefore, The value of k is 20.
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