" iv) "cos(A-B)=cos A cos B+sin A sin B

For all values of angle A and B(i)cos(A-B)=cos A cos B+sin A sin B(ii)cos(A+B)=cos A cos B-sin A sin B

Varify the formula for A=60^@ and B=30^@ . cos(A-B)=cos A cos B+sin A sin B

If A=60⁰ and B=30⁰ , verify that cos (A-B)=cos A cos B+sin A sin B

For any A,B in R, prove that cos(A-B)=cos A cos B+sin A sin B

Prove by vector methods. cos(A- B) = cos A cos B + sin A sin 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

If A=B=60o, verify that cos(A-B)=cos A cos B+sin A sin B(iii)sin(A-B)=sin A cos B-cos A sin B(iii)tan(A-B)=(tan A-tan B)/(1+tan A tan B)

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

If A,B,(A - B)are positive acute angles, then prove that geometrically : cos (A - B) = cos A cos B + sin A sin B

Find the value of cos 15^(@) using the relation cos (A - B) = cos A cos B + sin A sin B .