[tex]\frac{cos330^o}{ctg120^o}+sin^2225^o=\\\\=\frac{cos(360^o-30^o)}{ctg(90^o+30^o)}+sin^2(180^o+45^o)=\\\\=\frac{cos30^o}{-tg30^o}+(-sin^245^o)=\\\\=\frac{\sqrt3}{2}\ :\ (-\frac{\sqrt3}{3})+(\frac{\sqrt2}{2})^2=\\\\=\frac{\sqrt3}{2}\ \cdot\ (-\frac3{\sqrt3})+\frac24=\\\\=-\frac32+\frac12=\\\\=-\frac22=\\\\=-1[/tex]
