`c o s e ctheta=(x^2-y^2)/(x^2+y^2)` , where `x in R , y in R` given real `theta` if and only if

sin^2 theta =(x+y)^2/(4xy) where x,y in R gives theta if and only if

sin^(2)theta=((x+y)^(2))/(4xy) where x,y in R gives theta if and only if

Is costheta=(x^2-y^2)/(x^2+y^2) possible if x, y in R and 0 < theta < 90^@ ?

If cosec theta =(x^(2) - y^(2))/(x^(2) + y^(2)) , where x, y are two unequal nonzero real numbers then prove that theta has no real value.

If s e c^2theta=(4x y)/((x+y)^2) is true if and only if

If cosec theta = (x^(2) -y^(2))/(x^(2) + y^(2)) where x, y are two unequal non-zero real numbers then prove that theta has no real value.

Let f(x,y)=x^(2)+2xy+3y^(2)-6x-2y, where x, y in R, then

Let f(x,y)=x^(2)+2xy+3y^(2)-6x-2y, where x, y in R, then

Let R={(x,y):x^(2)+y^(2)=1,x,y in R} be a relation in R. Then the relation R is

Prove that the relation sin^(2)theta = (x+y)^(2)/4xy is not 4xy possible for any real theta where x in R , y in R such that |x | ne ly| .