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�� 1485. �� :�) (sin(?)+sin(?))^2+(cos(?)+cos(?))^2=4cos^2((?-?)/2);�) sin^2(x+y)-sin^2(x-y)=sin(2x)sin(2y);�)...

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1485. �� :

�) (sin(?)+sin(?))^2+(cos(?)+cos(?))^2=4cos^2((?-?)/2);

�) sin^2(x+y)-sin^2(x-y)=sin(2x)sin(2y);

�) cos^2(?+?)-cos^2(?-?)=-sin^2(?)sin(2?);

�) (sin(x)-sin(y))^2-(cos(x)-cos(y))^2=4sin^2((x-y)/2);

�) (sin(?)+sin(3?)+sin(5?))/(cos(?)+cos(3?)+cos(5?))=tg(3?);

�) sin(x)+sin(3x)+sin(5x)+sin(7x)=4cos(x)cos(2x)sin(4x).

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