If `x=2\ \ ` and `y=4,` then `(x/y)^(x-y)+\ (y/x)^(y-x)=`
(a) 4
(b) 8
(c) 12
(d) 2

If (x+y)^3-\ (x-y)^3-6y\ (x^2-y^2)=\ k y^3, then k= (a)1 (b) 2 (c) 4 (d) 8

If (x)/(x-y)=log((a)/(x-y)) then (dy)/(dx) is (a) (x)/(y), (b) 2-(x)/(y), (c) 2, (d) (x-y)/(x)

If the lengths of edges of a cuboid are 2x ,\ 3y\ a n d\ 4\ x y , then its volume is: (a) 24\ x y (b) 9x^2y (c) 24\ x^2y^2 (d) 6x^2y^2

X Y is drawn parallel to the base B C of Delta A B C cutting A B at X and A C at Y . If A B=4\ B X and Y C=2c m , then A Y= (a) 2c m (b) 4c m (c) 6c m (d) 8c m

The product of x\ a n d\ y is decreased by 4 is written as (a) 4-x y (b) x\ (y-4) (c) x y-4 (d) x y+4

Factorize: 4(x-y)^2-12(x-y)(x+y)+9(x+y)^2

Which of the following is a point on the common chord of the circle x^2+y^2+2x-3y+6=0 and x^2+y^2+x-8y-13=0? (1,-2) (b) (1,4) (c) (1,2) (d) 1,4)

If y^2=a x^2+b x+c , then y^3(d^2y)/(dx^2) is (a) a constant (b) a function of x only (c) a function of y only (d) a function of x and y

If y^2=a x^2+b x+c , then y^3(d^2y)/(dx^2) is (a) a constant (b) a function of x only (c) a function of y only (d) a function of x and y

If 3x+2y=12 and x y=6, find the value of 9x^2+4y^2