tgA+tgB+tgC=tgA·tgB·tgC
Siendo A, B y C ángulos de un triángulo(suman 180º)
tg(A+B)=-tg(180-(A+B))=-tgC
tg(A+B) = (tgA+tgB)/(1-tgA.tgB) = -tgC
<=> tgA + tgB = -tgC (1-tgA.tgB)
<=> tgA + tgB + tgC = tgA.tgB.tgC
Comments
tg(A+B)=-tg(180-(A+B))=-tgC
tg(A+B) = (tgA+tgB)/(1-tgA.tgB) = -tgC
<=> tgA + tgB = -tgC (1-tgA.tgB)
<=> tgA + tgB + tgC = tgA.tgB.tgC