fórmula de Graceli. 

   [sG log k/k [n]*p[n]*[w/√[n]* ]*[sG y / √[n] ]*p[n..]*[w/√[n] * x
e    =   cos [x] + [sG log k/k [n]*p[n]*[w/√[n]* ]*[sG y / √[n] ]*p[n..]*[w/√[n]   * sen [x].