If `cos(A-B)=3/5a n d\ t a n AtanB=2, t h e n` `cos A\ cosB=1/5` b. `cosA\ cos B=\ -1/5` c. `sin A\ sin B=\ -1/5` d. `sin A\ sin B=\ -1/5`

If A+B=pi/3a n d\ cos A+cos B=1,\ t h e n- a. cos(A-B)=1//3 b. \ |cos A-cos B|\ =sqrt(2/3) c. cos(A-B)=\ -1/3 d. \ |cos A-cos B|=1/(2sqrt(3))

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

In triangle ABC, right angled at B, if tanA=1/(sqrt3) . Find the value of cos A cos C - sin A sin C

Given that sin (A+ B) = sin A cos B + cos A sin B , find the value of sin 75° .

If A +B + C = pi then secA (cos B cos C - sin B sin C) = .........

For any "Delta"A B C the value of determinant |sin^2\ \ A cot A1sin^2B cot B1sin^2\ \ C cot C1| is equal to- s in A s in B s in C b. 1 c. 0 d. s in A+s in B+s in C

If A,B,C are the angles of a triangle then prove that cosA+cosB-cosC=-1+4cos(A/2)cos(B/2)sin(C/2)

Differentiate w.r.t.x the function in Exercises 1 to 11. cos( a cos x+ b sin x) , for some constant a and b.

In triangle ABC, right angled at B, if tanA=1/(sqrt3) . Find the value of sin A cos C + cos A sin C

In a triangle ABC, sin A- cos B = Cos C , then angle B is