`(y-x)(y+x)` is equal to

If x ,y ,a n dz are pth, qth, and rth terms, respectively, of an A.P. nd also of a G.P., then x^(y-z)y^(z-x)z^(x-y) is equal to a. x y z b. 0 c. 1 d. none of these

If x ,y ,a n dz are pth, qth, and rth terms, respectively, of an A.P. nd also of a G.P., then x^(y-z)y^(z-x)z^(x-y) is equal to x y z b. 0 c. 1 d. none of these

The solution of (dy)/(dx)=((x-1)^2+(y-2)^2tan^(- 1)((y-2)/(x-1)))/((x y-2x-y+2)tan^(- 1)((y-2)/(x-1))) is equal to

lim_(yto0) ((x+y)sec(x+y)-xsecx)/(y) is equal to

If x^(y)=e^(x-y) , then (dy)/(dx) is equal to

If 2^(x)+2^(y)=2^(x+y) then (dy)/(dx) is equal to

Let y = x^(x^(x...oo))," then " (dy)/(dx) is equal to

If y=sqrt(x+sqrt(y+sqrt(x+sqrt(y+...oo)))) , then (dy)/(dx) is equal to

If y=sin(log_(e)x) , then x^(2)(d^(2)y)/(dx^(2))+x(dy)/(dx) is equal to

tan^(-1)(x/y)-tan^(-1)((x-y)/(x+y)) is equal to (A) pi/2 (B) pi/3 (C) pi/4 (D) (-3pi)/4