If `cos (x-y)=3 * cos (x+y) , " then " cot x* cot y= `

If cos(x-y)=a cos(x+y), then cot x cot y is equal to

If a cos (x + y) = b cos (x - y), show that (a + b)tan x = (a - b) cot y.

If cot y =(sin(z+x))/(cos (z-x)-cos(z+x)),"show that" cot x , cot y "and" cotz "are in A.P."

If cot theta = cos (x+y) "and" cot phi = cos (x-y), "show that" tan (theta- phi)=(2sin x sin y )/(cos^(2) x + cos^(2) y)

If sin x + sin y + sin z = 0 and cos x + cos y + cos z = 0 then prove that cot (x+y)/2 = cot z and cos (x-y)/2 = pm 1/2

If cot (x+y)= 1/sqrt3, cot (x-y)= sqrt3 , then what are the smallest positive values of x and y respectively ?

If cos x=3 cos y, then 2 tan ((y-x)/(2))= ............. A) cot ((y-x)/(2)) B) cot ((x+y)/(4)) C) cot ((y-x)/(4)) D) cot ((x+y)/(2))

If cos x = tan y, cot y = tan z and cot z = tan x, then sin x =

If cosec^2x-cot^2y=1 then cos(x-y)=

If x+y+z=0 , show that : cot(x+y-z) cot (z+x-y) +(cot(x+y-z) cot (y+z-x)+ cot(y+z-x) cot (z+x-y)=1