Respostas

2014-03-17T17:19:06-03:00
F(1 + x) =  \frac{x}{ x^{2}  - 1}

1 + x = y ⇒ x = y - 1

f(y) =  \frac{y - 1}{ (y-1)^{2} -1 }

f(4) = \frac{4 - 1}{ (4-1)^{2} -1 } = \frac{3}{ (3)^{2} -1 } = \frac{3}{ 8 }