Find all the pairs of x,y that satisfy the equation `cosx+cosy+cos(x+y)=-3/2`

Find all the pairs of x,y that satisfy the equation cos x+cos y+cos(x+y)=-(3)/(2)

Find all number of pairs x,y that satisfy the equation tan^(4) x + tan^(4)y+2 cot^(2)x * cot^(2) y=3+ sin^(2)(x+y) .

Find all number of pairs x,y that satisfy the equation tan^4 x + tan^(4)y+2 cot^(2)x * cot^(2) y=3+ sin^(2)(x+y) .

Find all number of pairs x,y that satisfy the equation tan^(4) x + tan^(4)y+2 cot^(2)x * cot^(2) y=3+ sin^(2)(x+y) .

Find all number of pairs x,y that satisfy the equation tan^4) x + tan^(4)y+2 cot^(2)x * cot^(2) y=3+ sin^(2)(x+y) .

Find all number of pairs x,y that satisfy the equation tan^(4) x + tan^(4)y+2 cot^(2)x * cot^(2) y=3+ sin^(2)(x+y) .

If cosx+cosy-cos(x+y)=(3)/(2) then

Find all ordered pairs of real numbers that satisfy both the equations x^(2)+y^(2)=2xy and x^(2)+y^(2)=6x+6y+2

Find the number of pairs of integer (x , y) that satisfy the following two equations: {cos(x y)=x and tan(x y)=y (a) 1 (b) 2 (c) 4 (d) 6

Find the number of pairs of integer (x , y) that satisfy the following two equations: {cos(x y)=x and tan(x y)=y (a) 1 (b) 2 (c) 4 (d) 6