6*(sin(x)+cos(x))-2*sin(x)*cos(x)+6=0;
6*(sin(x)+cos(x))-2*sin(x)*cos(x)+7-(sin(x))^2-(cos(x))^2=0;
6*(sin(x)+cos(x))-(sin(x)+cos(x))^2+7=0;(sin(x)+cos(x))^2-6*(sin(x)+cos(x))-7=0;1).
(sin(x)+cos(x))=-1;
1+sin(x)+cos(x)=0; 2*(cos(0,5*x))^2+2*sin(0,5*x)*cos(0,5*x)=0;
cos(0,5*x1)=0; tg(0,5*x2)=-1