Question

What are the value of k, for which x2+5kx+16=0 has no real roots?

Answer 1

Answer:

-or + 8/5 = k

Answer 2

for no real root( b^2 - 4ac) has to be less than zero.

here we can write

(5K)^2 - 4*1*16. should be less than zero

25k^2- 64 less than zero

k^2 less than 64/25

ok K less than 8/5