Home
Class 11
MATHS
A point moves so that the sum of its dis...

A point moves so that the sum of its distances from `(a e ,0)a n d(-a e ,0)` is `2a ,` prove that the equation to its locus is `(x^2)/(a^2)+(y^2)/(b^2)=1` , where `b^2=a^2(1-e^2)dot`

Text Solution

Verified by Experts

Suppose that the co-ordinates of the point are (x , y), then the given condition
`sqrt([(x−ae)^2+y^2]) ​+sqrt([(x+ae)^2+y^2]) ​=2a .........(1) `
Now `[(x−ae)^2+y^2]−[(x+ae)^2+y^2]=−4aex ............(2) `
`[∵(a−b)^2−(a+b)^2=−4ab] `
On dividing (2) by (1), we get
...
Promotional Banner

Topper's Solved these Questions

  • BINOMIAL THEOREM

    RD SHARMA|Exercise Solved Examples And Exercises|228 Videos
  • COMBINATIONS

    RD SHARMA|Exercise Solved Examples And Exercises|117 Videos

Similar Questions

Explore conceptually related problems

A point moves so that the sum of its distances from (ae,0) and (-ae,0) is 2a, prove that the equation to its locus is (x^(2))/(a^(2))+(y^(2))/(b^(2))=1 where b^(2)=a^(2)(1-e^(2))

A point moves so that the sum of squares of its distances from the points (1,2) and (-2,1) is always 6. then its locus is

A(0,1) and B(0,-1) are 2 points.If a variable point P moves such that sum o its distance from A and B ia 4 Then the locus of P is the equation of the form of (x^(2))/(a^(2))+(y^(2))/(b^(2))=1 find the value of a^(2)+b^(2)

A point P(x,y) moves so that the sum of its distances from the points F(4,2) and F(-2,2) is 8 units.Find the equation of its locus and show that it is an ellipse.

If the sum of the distances of a moving point from two fixed points (ae, 0) and (-ae, 0) be 2a , prove that the locus of the point is: x^2/a^2+ y^2/(a^2 (1-e^2) =1

If the locus of the point which moves so that the difference (p)0 of its distance from the points (5,0) and (-5,0) is 2 is (x^(2))/(a^(2))-(y^(2))/(24)=1 then a is

Find the locus of a point such that the sum of its distances from the points (0,2) and (0,-2) is 6.

Find the locus of a point such that the sum of its distance from the points (0,2) and (0,-2) is 6.

Show that the equation of the locus of a point which moves so that the sum of its distance from two given points (k, 0) and (-k, 0) is equal to 2a is : x^2/a^2 + y^2/(a^2 - k^2) =1

A point moves so that the distance between the foot of perpendiculars from it on the lines ax^(2)+2hxy+by^(2)=0 is a constant 2d . Show that the equation to its locus is (x^(2)+y^(2))(h^(2)-ab)=d^(2){(a-b)^(2)+4h^(2)}

RD SHARMA-BRIEF REVIEW OF CARTESIAN SYSTEM OF RECTANGULAR COORDINATES-Solved Examples And Exercises
  1. A B is a variable line sliding between the coordinate axes in such ...

    Text Solution

    |

  2. A point moves so that the sum of its distances from (a e ,0)a n d(-a e...

    Text Solution

    |

  3. A point moves so that the sum of its distances from (a e ,0)a n d(-a e...

    Text Solution

    |

  4. Find the equation of the locus of a point which moves such that the ...

    Text Solution

    |

  5. Find the equation to the locus of a point equidistant from the points ...

    Text Solution

    |

  6. The sum of the squares of the distances of a moving point from two ...

    Text Solution

    |

  7. Find the locus of a point, such that the join of (-5,1)a n d(3,2) subt...

    Text Solution

    |

  8. Find the locus of a point such that the sum of its distances from the ...

    Text Solution

    |

  9. Find the locus of the mid-point of the portion of the line xcosalpha+y...

    Text Solution

    |

  10. A(5,3), B(3,-2) are two fixed points; find the equation to the locus o...

    Text Solution

    |

  11. Show that four points (0,-1),(6,7),(-2,3)a n d(8,3) are the vertices o...

    Text Solution

    |

  12. If the segments joining the points A(a , b)a n d\ B(c , d) subtends an...

    Text Solution

    |

  13. The vertices of a triangle are A(1,1),\ B(4,5)a n d\ C(6, 13)dot Find ...

    Text Solution

    |

  14. If the vertices of a triangle having integral coordinates . Prove that...

    Text Solution

    |

  15. If the coordinates of two points A and B are (3, 4) and (5,-2) , re...

    Text Solution

    |

  16. The coordinates of A ,B ,C are (6,3),(-3,5),(4,-2) , respectively, and...

    Text Solution

    |

  17. Find the coordinates of points lying on the line joining P(3,-4) and Q...

    Text Solution

    |

  18. Determine the ratio in which the line 3x+y-9=0 divides the segment ...

    Text Solution

    |

  19. Prove that: (4,-1) , (6,0) , (7,2) and (5,1)  are the vertices o a rh...

    Text Solution

    |

  20. if the coordinates of the mid points of the Sides of a triangle are (...

    Text Solution

    |