Question

If x=3 is one root of quadratic equation
$x{}^{2}-2kx - 6 = 0$
Then find the value of k

Answer 1

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Here is your answer

Given equation
$x {}^{2} - 2kx - 6 = 0$
$\alpha = 3 = x$
$3 {}^{2} - 2k3 - 6 = 0$
$9 - 6k - 6 = 0$
$3 - 6k = 0 \\ - 6k = - 3$
$k = 1 \div 2$