Q.

The domain of the function f(x)=19-x2 is

1 -3≤x≤3  
2 -3<x<3  
3 -9≤x≤9  
4 -9<x<9  

Ans.

(2)

f(x)=19-x2

Clearly,  9-x2>0⇒x2-9<0

⇒ (x+3)(x-3)<0.  Thus domain of f(x) is (-3,3).