If the sum of the zeroes of the polynomial $P(x)=( k^{2}-14)x^{2}-2x-12$ is $1$. Then find the value of $k$.


Given: The sum of the zeroes of the polynomial $P(x)=( k^{2}-14)x^{2}-2x-12$ is $1$. 

To do: To find the value of $k$.

Solution: 

The given polynomial is  $P(x)=( k^{2}-14)x^{2}-2x-12$

The sum of zeros of a quadratic equation is $-\frac{b}{a}$.

Hence, the sum of the zeros of the given quadratic equation$=-\frac{-2}{k^2-14}$

$=\frac{2}{k^2-14}$

As given, the sum of the zeroes is $1$.

$\Rightarrow \frac{2}{k^2-14}=1$

$\Rightarrow k^2-14=2$

$\Rightarrow k^2=14+2=16$

$\Rightarrow k=\pm\sqrt{16}$

$\Rightarrow k=\pm4$

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Updated on: 10-Oct-2022

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