diket f(x) = x + 1/x , g(x)= x- 1/x tentukan : f°g (x) dan g°f (x)

f•g(x) = f(g(x)) = f(x-1/x) = (x-1/x)+1/(x-1/x)
= (x-1/x + x/x) / (x-1/x) = (2x-1/x) / (x-1/x) = (2x-1/x)(x/x-1) = 2

f o g ( x ) = f (g(x))
              = f ( x - 1/x)
              = ( x - 1/x ) + 1/ x
              = x

g o f (x) = g (f(x))
            = g ( x + 1/x )
            = ( x + 1/x ) - 1/x
            = x