Question 1022220
the domain is restricted by where the denominator cannot be 0.  The numerator may be any number.
sqrt (9-x^2) cannot be 0
That means 9-x^2 cannot equal 0.
x^2=9 will make the denominator 0
x of +/- 3 will make the denominator 0 and cannot be in the domain.
(-oo,-3),(-3,3) and (3,oo) are the domain.