Question

The least integer k which makes the roots of the equation $x^{2} - 4x < 12\text{ is}$ imaginary is.

• A. 4
• B. 5
• C. 6
• D. 7

Answer 1

Answer: (D)

7

Answer 2

Roots are non real if discriminant < 0

i.e. if $5x^{2} - 7x + k = 0$ i.e. if $k$i.e. if $x^{2} - 7x + 6 = 0$

Hence, the required least integer k is 7.