For the quadratic equation

MATHEMATICS · Single correct · AoPS · Mathematics · Quadratic Equations - Part 2 · Quadratic Equations - Part 2

Problem

3x^2+2kx+5=0

, the roots are non-real. Which of the following describes all possible real values of

k

? (a)

|k|<\sqrt{60}

(b)

|k|>\sqrt{15}

(c)

|k|<\sqrt{15}

(d)

|k|\le\sqrt{15}