Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
COMEDK20269 May 2026Morning ShiftMathematicsEllipseActual

The length of the latus rectum of the curve represented by x = 3( t + t) and y = 4( t - t) is:

Options

  1. A9 2
  2. B9 2
  3. C32 2 3
  4. D9 2

Correct answer

B. 9 2

Step-by-step solution

Given parametric equations are: x = 3( t + t) x 3 = t + t y = 4( t - t) y 4 = t - t Squaring and adding both equations, we get: ( x 3 )^2 + ( y 4 )^2 = ( t + t)^2 + ( t - t)^2 x^2 9 + y^2 16 = 2( ^2 t + ^2 t) x^2 9 + y^2 16 = 2 x^2 18 + y^2 32 = 1 This represents an ellipse with a^2 = 18 and b^2 = 32 . Since b^2 > a^2 , the major axis lies along the y-axis. The length of the latus rectum is given by 2a^2 b . Substituting the values: Length of latus rectum = 2 18 32 = 36 4 2 = 9 2 Answer: 9 2

Practice Ellipse on Quantrex Academy →

More from Ellipse

The foci of a hyperbola are the same as those of the ellipse with equation 9x^2 + 16y^2 = 144 . If the length of the transverse axis of this hyperbola is 2 , then its equation is: 2026If the two ends of the major axis of an ellipse are (5, 0) and (-5, 0) and one focus lies on the line 3x - 5y - 9 = 0 , then its equation is 2026If P be any point on the ellipse 16x^2 + 25y^2 = 400 with foci S and S' and area of PSS' is 9 square units, then the abscissa of point P is........... 2026If is the eccentric angle of a point on the ellipse x^2 25 + y^2 9 = 1 such that the distance of the point from the center is 5 , then = ....... 2026The eccentricity of the ellipse represented by the equation 7x^2 + 16y^2 - 14x + 64y - 377 = 0 is... 2026A tangent having slope - 1 2 to the ellipse 3x^2 + 4y^2 = 12 intersects the X-axis and Y-axis at the points A and B respectively. if O is the origin, then the area of AOB is ... 2026If the eccentricity of the ellipse x^2 a^2 + y^2 b^2 = 1, (a > b) is 2 3 and its focal chord is 3x + 2y - 6 = 0 , then the value of a^2 + b^2 is... 2026If the line 3x + 4y + k = 0 touches the ellipse 9x^2 + 16y^2 = 144 , then the value of k is. 2026 Full Ellipse list All COMEDK PYQs