`sin^2 theta= (4xy)/(x+y)^2` is true if and only if (A) `x-y!=0` (B) `x=-y` (C) `x+y!=0` (D) `x!=0,y!=0`

sec^(2)theta = 4xy/(x+y)^(2) is true if and only if

sec^(2)theta=(4xy)/((x+y)^(2)) is true if and only if x+y!=0 (b) x=y,x!=0x=y( d ) x!=0,y!=0

If sec^(2)theta=(4xy)/((x+y)^(2)) is true if and only if x+y!=0( b) x=y,x!=0(c)x=y(d)x!=0,y!=0

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

Consider the parabola P touching x-axis at (1,0) and y-axis (0,2). Directrix of parabola P is : (A) x-2y=0 (B) x+2y=0 (C) 2x-y=0 (D) 2x+y=0

for every point (x,y,z) on the y-axis: (A) x=0,y=0 (B) x=0,z=0 (C) y=0,z=0 (D) y!=0,x=0,z=0

The equation of common tangent to the curves y^2 =4x and xy=2 is (A) x+2y-4=0 (B) x+2y+4=0 (C) x-2y+4=0 (D) x-2y-4=0

The image of line 2x+y=1 in line x+y+2=0 is : (A) x+2y-7=0 (B) 2x+y-7=0 (C) x+2y+7=0 (D) 2x+y+7=0

Find the equation of the tangent line to the curve y=(3x^2-1)/x at the point (1,2) is (a) 4x-y-1=0 (b) 4x+y+2=0 (c)x-y-1=0 (d) 4x-y-2=0