Question

3,4 примеры пожалуйста!

Answer 1

3) У меня буквы гамма нет, я буду писать a$cos(a)+ frac{2sin^2(a)-1}{sin(a)+cos(a)}= cos(a)+ frac{2sin^2(a)-sin^2(a)-cos^2(a)}{sin(a)+cos(a)}=$
$=cos(a)+ frac{sin^2(a)-cos^2(a)}{sin(a)+cos(a)} =cos(a)+ frac{(sin(a)+cos(a))(sin(a)-cos(a))}{sin(a)+cos(a)} =$
$=cos(a)+sin(a)-cos(a)=sin(a)$

4) $frac{1+ctg^2(x)}{tg(x)+ctg(x)} = frac{1+cos^2(x)/sin^2(x)}{tg(x)+ctg(x)} = frac{sin^2(x)+cos^2(x)}{sin^2(x)*(tg(x)+ctg(x))} =$
$= frac{1}{sin^2(x)*( frac{sin(x)}{cos(x)} + frac{cos(x)}{sin(x)} )} =frac{1}{sin^2(x)* frac{sin^2(x)+cos^2(x)}{sin(x)*cos(x)}} = frac{sin(x)*cos(x)}{sin^2(x)*1} =ctg(x)$