Consider the function y = √4-x.
What are the domain and range of this function?
a. domain: x≤ 4 , range: y≥ 0
b. domain: x≥ 2 , range: y≥ 2
c. domain: x≥ 4 , range: y≥ 0
d. domain: x≤ 2 , range: y≥ 2