Question

4x^2+kx-2=0 has no real roots if​

Answer 1

Answer:

The condition for real roots is that the parabola must touch or intersect the X Axis.

Only possible when D ≥ 0.

So,

b² - 4ac ≥ 0

k² - 32 ≥ 0

Use the wavy curve method to find the set of values that k belongs to.

k ∈ (-∞, -4√2] ∪ [4√2, ∞)

Answer 2

Step-by-step explanation:

Correct option is

C

Δ=k

2

−32

Given equation is:

4x

2

−kx+2=0

Discriminant = b

2

−4ac

a=4,b=−k,c=2

∴D=(k)

2

−4(2)(4)

=k

2

−32

∴Δ=k

2

−32