КП
Кристина Пегова
Ответ. (sin(a))^4+(cos(a))^4=((sin(a))^2+(cos(a))^2)^2-2*(sin(a)*cos(a))^2=
1-2*(sin(a)*cos(a))^2=1-0,5*(sin(2*a))^2; (sin(a)- cos(a))^2=1-2*sin(a)*cos(a)=2;
2*sin(a)*cos(a)=-1; sin(a)*cos(a)=-0,5; 1-2*(sin(a)*cos(a))^2=1-2*(-0,5)^2=0,5;