If PQ is a double ordinate of the hyperbola x2a2 - 

Subject

Mathematics

Class

JEE Class 12

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

21.

The line AB cuts off equal intercepts 2a from the axes. From any point P on the line AB perpendiculars PR and PS are drawn on the axes. Locus of mid-point of RS is

  • x + y = a

  • x2 + y2 = 4a2

  • x2 - y2 = 2a2


22.

X + 8y - 22 = 0, 5x + 2y -34 = 0, 2x - 3y + 13= 0 are the three sides of a triangle. The area of the triangle is

  • 36 sq units

  • 19 sq units

  • 42 sq units

  • 72 sq units


23.

The line through the points (a, b) and (- a,- b) passes through the point

  • (1, 1)

  • (3a, - 2b)

  • (a2, ab)

  • (a, b)


24.

The locus of the point of intersection of the straight  lines  where K is a non-zero real variable, is given by

  • a straight line

  • an ellipse

  • a parabola

  • a hyperbola


Advertisement
25.

The equation of a line parallel to the line 3x + 4y= 0 and touching the circle x2 + y2 = 9 in the first quadrant, is

  • 3x +4y = 15

  • 3x +4y = 45

  • 3x +4y = 9

  • 3x +4y = 27


26.

A line passing through the point of intersection of x + y = 4 and x - y = 2 makes an angle tan-134 with the x-axis. It intersects the parabola y2 = 4(x-3) at points x1 , y1 and x2, y2 respectively. Then, x1 - x2

  • 169

  • 329

  • 409

  • 809


27.

The equation of auxiliary circle of the ellipse 16x2 + 25y2 + 32x - 100y = 284 is

  • x2 + y2 + 2x - 4y - 20 = 0

  • x2 + y2 + 2x - 4y = 0

  • (x + 1)2 + (y - 2)2 = 400

  • (x + 1)2 + (y - 2)2 = 225


Advertisement

28.

If PQ is a double ordinate of the hyperbola x2a2 - y2b2 = 1 such that OPQ is equilateral. O being the centre. Then, the eccentricity e satisfies 

  • 1 < e < 23

  • e = 22

  • e = 32

  • e > 23


D.

e > 23

Given equation of hyperbola is x2a2 - y2b2 = 1 and OPQ is an equilateral triangle. PQ is double ordinate of the hyperbola.

Let the coordinates of P and Q be (asecθ, btanθ) and (asecθ, - btanθ), respectively.

In OPQ,OP = PQ a2sec2θ + b2tan2θ 2btanθ2 a2sec2θ = 3b2tan2θ sin2θ = a23b2

Now, sin2θ < 1

 a23b2 < 1 b2a2 > 13 1 + b2a2 > 43 e2 > 43 e > 23


Advertisement
Advertisement
29.

If the vertex of the conic y - 4y = 4x - 4a always lies between the straight lines x + y = 3 and 2x + 2y - 1 = 0, then

  • 2 < a < 4

  • - 12 < a < 2

  • 0 < a < 2

  • - 12 < a < 32


30.

limx11 + x2 + x1 - x1 - x is equal to

  • 1

  • does not exist

  • 23

  • ln2


Advertisement