For the quadratic equation to have no real roots

MATHEMATICS · Single correct · A Level · Mathematics · Algebra and Functions · Algebra and Functions

Problem

For the quadratic equation

2x^2+kx+3=0

to have no real roots, which of the following conditions on

k

must hold? (a)

|k|>\sqrt{24}

(b)

|k|\le \sqrt{24}

(c)

|k|<\sqrt{24}

(d)

|k|<\sqrt{12}