If f(x) = x^2 - 4, then what is f(f(1))?

[sql_lall]

Originally posted by Dilenger4
9 - 4 = 5 --> 4

I don't understand how to isolate f. It looks like f has to equal somthing then that somthing has to be squared ie. f(1) = f, f * f = f^2.

I think it's time to say d'oh.

Anyway, what do you mean by 'isolate f'??