Consider the quadratic function

MATHEMATICS · Single correct · CBSE · Mathematics · Quadratic Equations · Quadratic Equations

Problem

q(x)=2x^{2}+kx+8

. For which set of real numbers

k

q(x)>0

for all real

x

? (a)

k\in(-\infty,-8)\cup(8,\infty)

(b)

k\in(-4\sqrt{2},4\sqrt{2})

(c)

k\in(-8,8)

(d)

k=-8 \text{ or } k=8