Let the equation of an ellipse be . Then, the radius of the circle with centre (0, ) and passing through the foci of the ellipse is
9
7
11
5
The straight lines x + y = 0, 5x + y = 4 and x + 5y = 4 form
an isosceles triangle
an equilateral triangle
a scalene triangle
a right angled triangle
The value of for which the curve (7x + 5)2 + (7y + 3)2 = (4x + 3y - 24)2 represents a parabola is
Let f(x) = x + 1/2. Then, the number of real values of x for which the three unequal terms f(x), f(2x), f(4x) are in HP is
1
0
3
2
Let f(x) = 2x2 + 5x + 1. If we write f(x) as f(x) = a(x + 1)(x - 2) + b(x - 2)(x - 1) + c(x - 1)(x + 1) for real numbers a, b, c then
there are infinite number of choices for a, b, c
only one choice for a but infinite number of choices for b and c
exactly one choice for each of a, b, c
more than one but finite number of choices for a, b, c
If are the roots of ax2 + bx + c = 0 () and are the roots of px2 + qx + r = 0 (p 0), then the ratio of the squares of their discriminants is
a2 : p2
a : p2
a2 : p
a : 2p
The equation of the common tangent with positive slope to the parabola y2 = 8x and the hyperbola 4x2 - y2 = 4 is
A.
Equation of tangent in slope form of parabola is,
Also, tangent to the hyperbola 4x2 - y2 = 4 is,
c2 = a2m2 - b2
c2 = 1m2 - 4
i.e. m = is positive slope.
From Eq. (i),
The point on the parabola y2 = 64x which is nearest to the line 4x + 3y + 35 = 0 has coordinates
(9, - 24)
(1, 81)
(4, - 16)
(- 9, - 24)
Let z1, z2 be two fixed complex numbers in the argand plane and z be an arbitrary point satisfying Then, the locus of z will be
an ellipse
a straight line joining z1 and z2
a parabola
a bisector of the line segment joining z1 and z2
the coefficient of x8 in is equal to the coefficient of x- 8 in then a and b will satisfy the relation
ab + 1 = 0
ab = 1
a = 1 - b
a + b = - 1