If `2cos A = x+1/x` , `2cosbeta=y+1/y` then show that `2cos(A-B) =x/y+y/x`.

If 2 cos A=x+1/x, 2 cosB=y+1/y then show that 2 cos(A-B)=x/y + y/x .

If 2 cos A=x+1/x, 2 cosB=y+1/y then show that 2 cos(A-B)=x/y + y/x .

If 2 cos A=x+1/x, 2 cosB=y+1/y then show that 2 cos(A-B)=x/y + y/x .

(i) If tanA-tan B=x and cot B- cot A=y . Prove that cot(A-B)=1/x + 1/y . (ii) If 2 cos A = x+1/x, 2 cos B = y + 1/y , then show that 2 cos (A-B)= x/y+y/x .

(i) If tanA-tan B=x and cot B- cot A=y . Prove that cot(A-B)=1/x + 1/y . (ii) If 2 cos A = x+1/x, 2 cos B = y + 1/y , then show that 2 cos (A-B)= x/y+y/x .

If 2 cos alpha = x + (1)/(x) and 2 cos beta = y + (1)/(y) , show that (x)/(y) + (y)/(x) = 2 cos( alpha - beta)

If 2 cos alpha = x + (1)/(x) and 2 cos beta = y + (1)/(y) , show that x^(m) y^(n) + (1)/(x^(m)y^(n)) = 2 cos (m alpha + n beta)

If 2cos alpha = x + (1) / (x), 2cos beta = y + (1) / (y) then (x ^ (10)) / (y ^ (12)) - (y ^ (12)) / ( x ^ (10)) =

If 2 cos alpha = x + (1)/(x) and 2 cos beta = y + (1)/(y) , show that (x^(m))/(y^(n))- (y^(n))/(x^(m))= 2i sin (m alpha - n beta)

If 2cos theta=x+(1)/(x) and 2cos phi=y+(1)/(y) then