Example 6
If f (x) = 16x  log _{2 }x find f
Solution :
If f (x) = 16x  log_{2}x
\ f =
=
=
= 2  ( 2) log_{2} 2
= 2 + 2 (1) [ since^{.} log a a = 1]
= 4
Example 7
If y = f (x) = show
that x = f(y)
Solution :
y = f (x) =
Þ f (y) =
Putting y = we get
\ f (y) =
\ f (y) =
= x \ x = f (y)
Example 8
If f (x) =
find f { f [f(x)] }
Solution :
f (x) =
f [ f(x) ] =
\ f [ f(x) ] =
and f { f [f(x)] } =
\ f { f [f(x)] } = x
