Question

For what value of k x^2-kx+4=0 has real and equal roots.

Answer 1

For real and equal roots
D=0
${b}^{2} - 4ac = 0 \\ {b}^{2} = 4ac \\ {( - k)}^{2} = 4(k)(4) \\ {k}^{2} = 16k \\ k = 16$