Example 12 - Find equation: foci (0, 5), major axis 20 - Ellipse - Defination

Slide28.JPG
Slide29.JPG

  1. Chapter 11 Class 11 Conic Sections
  2. Serial order wise

Transcript

Example 12 Find the equation of the ellipse, whose length of the major axis is 20 and foci are (0, 5). We need to find equation of ellipse Whose length of major axis = 20 & foci are (0, 5) Since the foci are of the type (0, c) So the major axis is along the y-axis & required equation of ellipse is + = 1 From (1) & (2) c = 5 Given length of major axis = 20 & we know that Length of major axis = 2a 20 = 2a 2a = 20 a = 20 2 a = 10 Also We know that c2 = a2 b2 (5) 2 = (10) 2 b2 b2 = (10) 2 (5) 2 b2 = 100 25 b2 = 75 Equation of ellipse is 2 2 + 2 2 = 1 Putting value 2 75 + 2 (10) 2 = 1 + = 1

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.