producte integral tangent

TAN_{x}[f(x)] = ( 1/(1+( f(x) )^{2}) )·d_{x}[f(x)]


TAN_{x}[tan(x)] = 1


f(x) [o( tan(x) )o] g(x) = ∫ [ TAN_{x}[f(x)]·TAN_{x}[g(x)] ] TAN[x]


f(x) [o( tan(x) )o] tan(x) = f(x)


f(x) [o( tan(x) )o] ( f(x) )^{[o( tan(x) )o](-1)} = tan(x)