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

If sin A=(1)/(sqrt(5)) and sin B=(1)/(sqrt(10)) ,find the values of cos A and cos B .Hence using the formula cos(A+B)=cos A cos B-sin A sin B, show that (A+B)=45^(@).

sin A-sin B and cos A + cos B

If sin (A-B)=sin A cos B-cos A sin B and cos (A - B) = cos A cos B + sin A sin B . find the values of sin 15^@ and cos 15^@.

In a Delta ABC ,angle C=90^(@)and tan A=(1)/(sqrt(3)). find the values of : (i) (sin A*cos B+ cos A*sin B ) " " (ii) (cos A*cos B-sin A*sin B)

Prove that a cos A+b cos B+c cos C=4R sin A sin B sin C

If A - B = (pi)/(3) , then find cos A cos B + sin A sin B.

What is the value of sin (B - C) cos (A- D) + sin (A-B) cos (C -D) + sin (C- A) cos (B - D) ? sin (B - C) cos (A- D) + sin (A-B) cos (C -D) + sin (C- A) cos (B - D) का मान क्या है?

If sin A=sin B and cos A=cos B then A=

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