For which values of does the function yield real values for every real ?

MATHEMATICS · Single correct · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation

Problem

For which values of

m

does the function

f(x)=\sqrt{x^{2}-4x+m}

yield real values for every real

x

? (a)

m>4

(b)

m\ge 4

(c)

m\le 4

(d)

m=4