Find the range of each of the following functions. All the functions are defined for the largest possible domain of values of x.
a) f(x) = √(4-x^2) b) f(x) = √(4-x)
The Attempt at a Solution
The answers given are a) 0 ≤ f(x) ≤ 2 b) f(x) ≥ 0 . But my answers are a) -2≤ f(x)≤2 b) All real numbers . Can anyone explain what i had done wrong? Why negative numbers are excluded?