SIN(α)·√(1 + COT(α)^2)
Benutze COT(α) = COS(α)/SIN(α)
= SIN(α)·√(1 + COS(α)^2/SIN(α)^2)
= SIN(α)·√(SIN(α)^2/SIN(α)^2 + COS(α)^2/SIN(α)^2)
= SIN(α)·√((SIN(α)^2 + COS(α)^2)/SIN(α)^2)
Benutze SIN(α)^2 + COS(α)^2 = 1
= SIN(α)·√(1/SIN(α)^2)
Das wars eigentlich schon.