Q.

The range of the function f(x)=9-x2 is

1 [0, 3]  
2 (0, 3]  
3 (0, 3)  
4 [0, 3)  

Ans.

(1)

Let y=9-x2⇒y2=9-x2

⇒x2=9-y2⇒x=9-y2

Clearly, 9-y2≥0⇒y2≤9⇒-3≤y≤3

But y≥0. Hence, 0≤y≤3