If `x ,y in Ra n d2x^2+6x y+5y^2=1,t h e n` `|x|lt=sqrt(5)` b. `|x|geqsqrt(5)` c. `y^2lt=2` d. `y^2lt=4`

x+y lt 5

If x ,y in R satify the equation x^2+y^2-4x-2y+5=0, then the value of the expression [(sqrt(x)-sqrt(y))^2+4sqrt(x y)]//(x+sqrt(x y)) is a. sqrt(2)+1 b. (sqrt(2)+1)/2 c. (sqrt(2)-1)/2 d. (sqrt(2)+1)/(sqrt(2))

The equation of the line that touches the curves y=x|x| and x^2+(y^2-2)^2=4 , where x!=0, is y=4sqrt(5)x+20 (b) y=4sqrt(3)x-12 y=0 (d) y=-4sqrt(5)x-20

2x-3y lt 6

xy=( x+y )^n and dy/dx = y/x then n= 1 b. 2 c. 3 d. 4

If x ,y ,z are real and 4x^2+9y^2+16 z^2-6x y-12 y z-8z x=0,t h e nx , y,z are in a. A.P. b. G.P. c. H.P. d. none of these

2x-y gt 1, x-2y lt -1

The centers of a set of circles, each of radius 3, lie on the circle x^2+y^2=25 . The locus of any point in the set is (a) 4lt=x^2+y^2lt=64 (b) x^2+y^2lt=25 (c) x^2+y^2geq25 (d) 3lt=x^2+y^2lt=9

x+y ge 4, 2x-y lt 0