Question

If x = 3 is one of the roots of a quadratic equation $x^2-2kx-6=0$, then find the value of k.

Answer 1

Given quadratic equation is,
$x^2-2kx-6=0$
x = 3 is a root of above equation, then
$(3{)}^2-2k(3)-6=09-6k-6=03-6k=03=6k\therefore k=\frac{3}{6}=\frac{1}{2}k=\frac{1}{2}$