[tex]\frac{1-cos\alpha}{sin\alpha}+\frac{sin\alpha}{1-cos\alpha}=\frac{2}{sin\alpha}\\\\L=\frac{1-cos\alpha}{sin\alpha}+\frac{sin\alpha}{1-cos\alpha}=\frac{(1-cos\alpha)^2}{sin\alpha(1-cos\alpha)}+\frac{sin^2\alpha}{sin\alpha(1-cos\alpha)}=\\\\\frac{1-2cos\alpha+cos^2\alpha+sin^2\alpha}{sin\alpha(1-cos\alpha)}=\frac{1-2cos\alpha+1}{sin\alpha(1-cos\alpha)}=\\\\\frac{2-2cos\alpha}{sin\alpha(1-cos\alpha)}=\frac{2(1-cos\alpha)}{sin\alpha(1-cos\alpha)}=\frac{2}{sin\alpha}=P[/tex]
Część druga w załączniku
