Question

For what value of k the quadratic equation x2-kx+4=0 has equal roots

Answer 1

Answer:

The values of $k$ are -4 and 4.

Step-by-step explanation:

A quadratic equation of the form $ax^2+bx+c$ has equal root if the discriminant

$b^2-4ac=0$

Given the quadratic equation,

$x^2-kx+4=0$

This equation has equal roots. So the discriminant must be zero. Thus we have,

$\implies (-k)^2-4\times 4\times 1=0\\\\\implies k^2-16=0\\\\\implies k^2=16\\\\\implies k= \pm4$

Thus the values of $k$ are -4 and 4