Find the domain and range for y=x^2+9.

Question

Wouldn't the domain and range just be all real numbers since nothing else is really given in the equation? How would you enter "all real numbers" in interval notation? Would it include the infinity sign?

Answer 1

domain is all reals, but since x^2 >= 0 for all x,

y >= 9 for all x.
That is the range.

D: (-∞,+∞)
R: [9,∞)