[cos^(2)((pi)/(4)+theta)-sin^(2)((pi)/(4)-theta)=?],[(a)0quad (b)sin2 theta]

Prove that: cos^(2)((pi)/(4)-theta)-sin^(2)((pi)/(4)-theta)=s in2 theta

(1-tan^(2)((pi)/(4)-theta))/(1+tan^(2)((pi)/(4)-theta))=sin2 theta

If : sin^(2) ((pi)/(4) + (theta)/(2)) - cos^(2) ((pi)/(4) + (theta)/(2))= A) sin theta B) cos theta C) sin 2 theta D) cos 2 theta

Prove that: cos^2(pi/4-theta)-sin^2(pi/4-theta)=sin2theta

Prove that cos^2(pi/4-theta)-sin^2(pi/4-theta)=sin 2theta

2cos((pi)/(2)-theta)+3sin((pi)/(2)+theta)-(3sin theta+2cos theta)=

sin theta+sin((2 pi)/(3)+theta)+sin((4 pi)/(3)+theta)=0

sin""((pi)/2+ theta ) * cos (pi- theta ) * cot ""((3pi)/(2)+ theta ) - sin""((pi)/2- theta ) * sin""((3pi)/2 - theta ) * cot ""((pi)/2 + theta ) =

Prove that 4sin theta sin((pi)/(3)+theta)sin((2 pi)/(3)+theta)=sin3 theta

Prove that : cos (pi/4- theta)cos (pi/4-phi)-sin(pi/4-theta) sin (pi/4-phi)= sin (theta+phi) .