[tex]\frac{sin\alpha-cos\alpha}{sin\alpha}=\frac{sin\alpha}{sin\alpha}-\frac{cos\alpha}{sin\alpha}=1-tg\alpha=1-\frac{2}{3}=\frac{1}{3}[/tex]
[tex]\frac{2-2sin^2\alpha}{sin^2\alpha}=\frac{2(1-sin^2\alpha)}{sin^2\alpha}=\frac{2cos^2\alpha}{sin^2\alpha}=2ctg^2\alpha=2\cdot(\frac{1}{tg\alpha})^2=2\cdot(\frac{3}{2})^2=2\cdot\frac{9}{4}=\frac{9}{2}[/tex]
