Home
Class 12
MATHS
Suppose (h, k) lies on the circle x^2 + ...

Suppose (h, k) lies on the circle `x^2 + y^2` =4, then (2h + 1, 3k + 2) lies on an ellipse with eccentricity e, then `e^2` equals

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the eccentricity \( e \) of the ellipse defined by the transformation of points from the circle \( x^2 + y^2 = 4 \). ### Step-by-Step Solution: 1. **Identify the Circle**: The equation of the circle is given by: \[ x^2 + y^2 = 4 \] This means that the radius of the circle is \( r = 2 \) and it is centered at the origin \( (0, 0) \). 2. **Parameterize the Circle**: Any point \( (h, k) \) on the circle can be expressed in terms of a parameter \( \theta \): \[ h = 2 \cos \theta, \quad k = 2 \sin \theta \] 3. **Transform the Point**: We need to find the new point \( (x', y') \) defined by: \[ x' = 2h + 1 = 2(2 \cos \theta) + 1 = 4 \cos \theta + 1 \] \[ y' = 3k + 2 = 3(2 \sin \theta) + 2 = 6 \sin \theta + 2 \] 4. **Express in Terms of \( x' \) and \( y' \)**: We can rewrite the expressions for \( x' \) and \( y' \): \[ x' - 1 = 4 \cos \theta \quad \Rightarrow \quad \cos \theta = \frac{x' - 1}{4} \] \[ y' - 2 = 6 \sin \theta \quad \Rightarrow \quad \sin \theta = \frac{y' - 2}{6} \] 5. **Use the Pythagorean Identity**: Since \( \cos^2 \theta + \sin^2 \theta = 1 \), we substitute: \[ \left(\frac{x' - 1}{4}\right)^2 + \left(\frac{y' - 2}{6}\right)^2 = 1 \] 6. **Simplify the Equation**: This leads to: \[ \frac{(x' - 1)^2}{16} + \frac{(y' - 2)^2}{36} = 1 \] This is the standard form of an ellipse. 7. **Identify \( a^2 \) and \( b^2 \)**: From the equation, we have: \[ a^2 = 16 \quad \text{and} \quad b^2 = 36 \] 8. **Calculate the Eccentricity**: The eccentricity \( e \) of the ellipse is given by: \[ e = \sqrt{1 - \frac{a^2}{b^2}} = \sqrt{1 - \frac{16}{36}} = \sqrt{1 - \frac{4}{9}} = \sqrt{\frac{5}{9}} = \frac{\sqrt{5}}{3} \] 9. **Find \( e^2 \)**: Finally, we need \( e^2 \): \[ e^2 = \left(\frac{\sqrt{5}}{3}\right)^2 = \frac{5}{9} \] ### Final Answer: Thus, \( e^2 = \frac{5}{9} \).
Promotional Banner

Topper's Solved these Questions

  • ELLIPSE

    MCGROW HILL PUBLICATION|Exercise Exercise (Single Correct)|15 Videos
  • ELLIPSE

    MCGROW HILL PUBLICATION|Exercise Exercise (Level 1 Single Correct)|25 Videos
  • ELLIPSE

    MCGROW HILL PUBLICATION|Exercise Solved Examples (Level 2 Single Correct Answer)|10 Videos
  • DIFFERENTIAL EQUATIONS

    MCGROW HILL PUBLICATION|Exercise Questions from Previous Years. B-Architecture Entrance Examination Papers|14 Videos
  • HEIGHTS AND DISTANCES

    MCGROW HILL PUBLICATION|Exercise QUESTIONS FROM PREVIOUS YEARS. B-ARCHITECTURE ENTRANCE EXAMINATION PAPERS|3 Videos

Similar Questions

Explore conceptually related problems

Suppose (h,k) lies on the circle x^(2)+y^(2)=4 , and (2h+1,3k+2) lies on an ellipse with eccentricity e, then 9e^(2) equals

3x^2+4y^2-6x+8y+k=0 represents an ellipse with eccentricity 1/2,

If P is a variable point on the ellipse (x^(2))/(a^(2))+(y^(2))/(b^(2))=1 whose focii are S' and S and e_(1) is the eccentricity and the locus of the inceose centre of Delta PSS is an ellipse whose eccentricity is e_(2), then the value of (1+(1)/(e_(1)))e_(2)

If the variable line y=kx+2h is tangent to an ellipse 2x^(2)+3y^(2)=6 then locus of P(h,k) is a conic C whose eccentricity is e then the value of 3e^(2) is

If the variable line y=kx+2h is tangent to an ellipse 2x^(2)+3y^(2)=6, then the locus of P(h,k) is a conic C whose eccentricity is 3 . Then the value of 3e^(2) is

Let E be an ellipse such that x+y= 2sqrt5 is a tangent to E and E passes through (3,-1). If axes of E are along the coordinates axes and e is the eccentricity of E, then e^2 equals _____

If the circle whose diameter is the major axis of the ellipse (x^(2))/(a^(2))+(y^(2))/(b^(2))=1(a gt b gt 0) meets the minor axis at point P and the orthocentre of DeltaPF_(1)F_(2) lies on the ellipse, where F_(1) and F_(2) are foci of the ellipse, then the square of the eccentricity of the ellipse is