Question

All values of k for which 2x^2 - kx + 8 = 0 has real root is

Answer 1

If equal

b^2= 4ac

k^2= 4×8×2

k^2= 16× 4

k= +8

If not equal

b^2- 4ac >0

k^2-64> 0

k^2>64

k> -+8

k= any value above 8

So values of k are 8 and numbers above 8