Ex 11.2, 6 - x2 = -9y, find focus, axis, directrix, latus

Ex 11.2,  6 - Chapter 11 Class 11 Conic Sections - Part 2
Ex 11.2,  6 - Chapter 11 Class 11 Conic Sections - Part 3

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

Transcript

Ex 11.2, 6 Find the coordinates of the focus, axis of the parabola, the equation of directrix and the length of the latus rectum for x2 = –9y Given equation is x2 = –9y. Since the above equation is involves x2 Its axis is y-axis Also coefficient of y is negative (−) Hence we use equation x2 = − 4ay Comparing x2 = −9y & x2 = −4ay From (1) & (2) −4ay = −9y a = (−9𝑦)/(−4𝑦) a = 9/4 Coordinate of focus is (0, −a) i.e. focus ("0, " (−𝟗)/𝟒) Equation of Directix is y = a y = 𝟗/𝟒 Latus Rectum is 4a = 4 × 9/4 = 9

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.