values of k for which kx^2 - 2kx + 5 = 0 has no soln

Hi everyone I have struggling on a question:

Find the values of k for which the equation kx^2-2kx+5=0 has no root

I know that I would have to use the descriminant:

b^2 - 4ac < 0
a = k, b = 2k, c = 5
2k^2 - 4 (K) (5)
2k^2 - 20 k

What do I do after this stage?

Re: Miscellaneous 6 OCR

Hint:
Discriminant = 4k^2 - 20k = 4k(k - 5)

sqrt[4k(k - 5)]
= 2sqrt(k)sqrt(k - 5)

Re: Miscellaneous 6 OCR

I still don't understand how you the eqation above. are the number squared

Re: Miscellaneous 6 OCR

Set 4k[sup:1kb4f5hu]2[/sup:1kb4f5hu]-20k<0 to get 0<k<5.