" 9."cos(A+B)cos(A-B)-sin(A+B)sin(A-B)

The value of [cos (A-B) cos (A+B) -sin (A-B) sin (A+B)] is-

Prove that: i) sin(A+B)cos(A-B)-cos(A+B)sin(A-B)=sin2B ii) cos(45^(@)-A)cos(45^(@)-B)-sin(45^(@)-A)sin(45^(@)-B)=sin(A+B)

Prove that: i) sin(A+B)cos(A-B)-cos(A+B)sin(A-B)=sin2B ii) cos(45^(@)-A)cos(45^(@)-B)-sin(45^(@)-A)sin(45^(@)-B)=sin(A+B)

sin(A+B). cos(A-B)+sin(A-B). cos(A+B)=

Prove (i)cos(A+B)+cos(A-B)=2cos A cos B(ii)cos(A-B)-cos(A+B)=2sin A sin B

Prove that: (cos(A+B+C)+cos(-A+B+C)+cos(A-B+C)+cos(A+B-C))/(sin(A+B+C)+sin(-A+B+C)+sin(A-B+C)-sin(A+B-C))=

(sin(A+B)+cos A-sin(A-B))/(cos(A-B)+sin A-cos(A+B))=

Prove that (sin A+sin B)/(cos A+cos B)+(cos A-cos B)/(sin A-sin B)=0

Show that (1+sin A)/(cos A)+(cos B)/(1-sin B)=(2sin A-2sin B)/(sin(A-B)+cos A-cos B)

If A=30o and B=60o ,verify that sin(A+B)=sin A cos B+cos A sin B(ii)cos(A+B)=cos A cos B-sin A sin B