Question

If x = 3 is one root of the quadratic equation x square– 2kx – 6 = 0, then find the value of k.

Answer 1

-2kx-6=0

put value of x

(-2)k(3)-6=0

-6k=0

k=0

Answer 2

Given eqn:-

${x}^{2} - 2kx - 6 = 0$

And, x = 3

Simply put the value of x on the given equation.

${3}^{2} - 2k(3) - 6 = 0 \\ \\ 9 - 6k - 6 = 0 \\ \\ 3 - 6k = 0 \\ \\ 3 = 6k \\ \\ k = \frac{3}{6} \\ \\ k = \frac{1}{2}$

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