Home
Class 12
MATHS
If the reflection of the ellipse ((x-4)^...

If the reflection of the ellipse `((x-4)^(2))/(16)+((y-3)^(2))/(9) =1` in the mirror line `x -y -2 = 0` is `k_(1)x^(2)+k_(2)y^(2)-160x -36y +292 = 0`, then `(k_(1)+k_(2))/(5)` is equal to

A

4

B

5

C

6

D

7

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the reflection of the given ellipse in the mirror line and then compare it with the given equation to find the values of \( k_1 \) and \( k_2 \). ### Step-by-Step Solution: 1. **Identify the Ellipse Equation:** The given ellipse is: \[ \frac{(x-4)^2}{16} + \frac{(y-3)^2}{9} = 1 \] This can be rewritten in standard form as: \[ (x - 4)^2 + \frac{(y - 3)^2}{\frac{9}{16}} = 1 \] Here, \( h = 4 \), \( k = 3 \), \( a = 4 \), and \( b = 3 \). 2. **Finding a Point on the Ellipse:** A point on the ellipse can be expressed as: \[ (x, y) = (4 + 4 \cos \theta, 3 + 3 \sin \theta) \] 3. **Equation of the Mirror Line:** The mirror line is given by: \[ x - y - 2 = 0 \] This can be rewritten as: \[ x - y = 2 \] 4. **Finding the Image of the Point:** To find the reflection of the point \( (4 + 4 \cos \theta, 3 + 3 \sin \theta) \) across the line \( x - y - 2 = 0 \), we use the formula for reflection across a line \( Ax + By + C = 0 \): \[ h' = \frac{(b^2 - a^2)x_1 - 2ab y_1 - 2ac}{a^2 + b^2} \] \[ k' = \frac{(a^2 - b^2)y_1 - 2ab x_1 - 2bc}{a^2 + b^2} \] Here, \( A = 1, B = -1, C = -2 \), \( x_1 = 4 + 4 \cos \theta \), and \( y_1 = 3 + 3 \sin \theta \). 5. **Calculating the Reflection:** After applying the reflection formulas, we get: \[ h' = 3 + 5 \sin \theta \] \[ k' = 4 \cos \theta + 2 \] 6. **Finding the Locus of the Reflected Points:** We now express the locus of the reflected points \( (h', k') \) in terms of \( x \) and \( y \): \[ x - 5 = 3 \sin \theta \quad \text{and} \quad y - 2 = 4 \cos \theta \] Using the identity \( \sin^2 \theta + \cos^2 \theta = 1 \), we substitute: \[ \left(\frac{x - 5}{3}\right)^2 + \left(\frac{y - 2}{4}\right)^2 = 1 \] 7. **Expanding the Locus Equation:** Expanding this equation gives: \[ 16(x - 5)^2 + 9(y - 2)^2 = 144 \] Simplifying leads to: \[ 16x^2 + 9y^2 - 160x - 36y + 292 = 0 \] 8. **Comparing with Given Equation:** The reflected ellipse is given in the form: \[ k_1 x^2 + k_2 y^2 - 160x - 36y + 292 = 0 \] Comparing coefficients, we find: \[ k_1 = 16, \quad k_2 = 9 \] 9. **Calculating \( \frac{k_1 + k_2}{5} \):** Now, we calculate: \[ \frac{k_1 + k_2}{5} = \frac{16 + 9}{5} = \frac{25}{5} = 5 \] ### Final Answer: Thus, the value of \( \frac{k_1 + k_2}{5} \) is \( 5 \).

To solve the problem, we need to find the reflection of the given ellipse in the mirror line and then compare it with the given equation to find the values of \( k_1 \) and \( k_2 \). ### Step-by-Step Solution: 1. **Identify the Ellipse Equation:** The given ellipse is: \[ \frac{(x-4)^2}{16} + \frac{(y-3)^2}{9} = 1 ...
Promotional Banner

Topper's Solved these Questions

  • ELLIPSE

    CENGAGE|Exercise Multiple Correct Answers Type|6 Videos
  • DOT PRODUCT

    CENGAGE|Exercise DPP 2.1|15 Videos
  • ELLIPSE AND HYPERBOLA

    CENGAGE|Exercise Question Bank|28 Videos

Similar Questions

Explore conceptually related problems

If the equation on reflection of ((x-4)^(2))/16+((y-3)^(2))/9=1 about the line x-y-2=0 is 16x^(2)+9y^(2)+k_(1)x-36y+k_(2)=0 then (k_(1)+k_(2))/22 is

(x^(2))/(16-k)+(y^(2))/(k-9)=1 represents ellipse if

If y = 2x + k " touches " x^(2) + y^(2) - 4x - 2y = 0 , then k=

If line 2x - y + k = 0 is a diameter of circle x^(2) + y^(2) + 6x - 6y + 5 = 0 , then k =

If the equation (x^(2))/(16 -K) + (y^(2))/(5-K) = 1 represents an ellipse , then

If the line y=x+k touches the ellipse 9x^(2)+16y^(2)=144 ,then the absolute difference of the values of k is

If e_(1) and e_(2) are the eccentricities of the ellipse (x^(2))/(18)+(y^(2))/(4)=1 and the hyperbola (x^(2))/(9)-(y^(2))/(4)=1 respectively and (e_(1), e_(2)) is a point on the ellipse 15x^(2)+3y^(2)=k , then the value of k is equal to

If the line 3x - 4y - k = 0 (k gt 0) touches the circle x^(2)+y^(2)-4x-8y-5 =0 at (a, b) then k + a + b is equal to :-

If line 4x + 3y + k = 0 " touches circle " 2x^(2) + 2y^(2) = 5x , then k =

If x + y+ k =0 touches the circle x ^(2) + y^(2) -2x -4y + 3 =0, then k can be