Question

How do you determine the range of a radical function such as f(x) = 3- sqrt (2x+5)

Answer 1

Well, if f is a function mapped to the real numbers, x cannot be less than 5/2, which would leave us with a range as follows:
\[3 \le f(x) \le \infty\]

Answer 2

Pardon, it should be strictly less than infinity. ;p

Answer 3

Got it. Thanks very much.