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
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)
A.
(9, - 24)
Given equation of parabola is,
y2 = 64x
The point at which the tangent to the curve is parallel to the line is the nearest point on the curve.
On differentiating both sides of Eq. (i), we get
Also, slope of the given line is
Therefore, the required point is (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