1) The foci of the ellipse x2/16 + y2/b2 = 1 and the hyperbola x2/144 - y2/81 = 1/25 coinside. Then the value of b2 is

a )   5

b )   7

c )   9

d )   1

2) The normal at point (b t12, 2b t1) on a parabola meets the parabola again in the point (b t22, 2b t2)

a )   t2 = - t1 + 2/t1

b )   t2 = t1 - 2/t1

c )   t2 = t1 + 2/t1

d )   t2 = - t1 - 2/t1

3) If th etwo circles (x - 1)2 + (y - 3)2 = r2 and x2 + y2 -8x + 2y + 8 = 0 intersect in two distinct points , then

a )   r < 2

b )   r = 2

c )   r > 2

d )   2 < r < 8

4) The degree and order of the differential equation of the family of all parabolas whose axis is x-axis , are respectively

a )   1 , 2

b )   3 , 2

a )   2 , 3

d )   2 , 1

ANSWERS