For what real values of does the function possess at least one real input in its domain?

MATHEMATICS · Single correct · IB Diploma Programme · Mathematics: Analysis and Approaches · Functions · Functions

Problem

For what real values of

k

does the function

f_k(x)=\sqrt{x+k}+\sqrt{5-2x}

possess at least one real input

x

in its domain? (a)

k\le -\dfrac52

(b)

k=-\dfrac52

(c)

k\ge -\dfrac52

(d)

k>-\dfrac52