fórmula de Graceli. 

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