Question

For what value of k the quadratic equation x×x -kx+4 =0 has equalroots

Answer 1

if D=0, then an equation has equal roots...

And D = √b^2 - 4ac

So 0 = √ (-k)^2 - 4(1)(4)
0 = √ (k)^2 - 16

Squaring both sides

0 = k^2 - 16
16 = k^2
√16 = k
4 = k

Hence for k=4 , the given equation has equal roots.