For range of function f(x) = tan(pi2 /9-x2) :-
f(x) = tan(pi2/9-x2)
First find the range of values of x that can be used in this equation, so,
x = (-3,3) [Since , if the values of x will be greater or equal to 3, the value of pi2/9-x2 will become infinite]
Now,
Minimum value of f(x) = tan{pi2/9-(3)2}
=tan{pi2/9-(9)}
=tan(0)
=0
Maximum value of f(x) = tan{pi2/9-(0)2}
= tan{pi2/9}
= tan{pi/3}2
= {tan(pi/3)}2
= (root3)2
= 3
Therefore, range of function f(x) = [0,3]