badge image

Enroll For Free Now & Improve Your Performance.

×
User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 12

                        

If lines 2x + 3y =10 and 2x-3y =10 are tangents at the extremities of a latus rectum of an ellipse whose centre is origin,then the length of the latus rectum is?

4 years ago

Answers : (1)

Faiz
107 Points
							You know both the tangents...Their point of intersection is (5,0)...You can use the formula of pair of tangents from a point drwn from  (x`, y`)....that is SS` - T² = 0......S= x²/a² + y²/b² - 1 = 0...S`= x`²/a² + y`²/b² - 1 = 0...T= xx`/a² + yy`/b² - 1 = 0...Here (x`,y`) is (5,0)....Multiply the given tangents and then compare the coefficients....A little simplified form which you will get is:::: x²/a² + y²/b²*(1- 25/a²) - 10x/a² + (25/a²) = 0....And product of tangents is:::: 4x² - 9y² - 40x + 100 = 0.....Now comapre the coefficients...from which you will get a²=1/4 and b²=11...which gives length of the latus ractum as ans:::: 44 units......
						
3 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 101 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details