0

Guest

Courses New

If CF is the perpendicular from the centre C f ellipse x2/a2+ y2/b2 = 1 on the tangent at any point P & G is the point when the normal at P meets the major axis , then CF PG equals to (a) a2 (b) ab (c) b2 (d) b3 plzz explain..!!

If CF is the perpendicular from the centre C f ellipse x2/a2+ y2/b2 = 1 on the tangent at any point P & G is the point when the normal at P meets the major axis , then CF PG equals to


(a) a2                    (b) ab


(c) b2                     (d) b3 


plzz explain..!!

Grade:11

1 Answers

M Murali Krishna
33 Points
8 years ago
Equation of tangent at
P(a costhita, b sinthita) on ellipse is
(x costhita/a) + ( y sinthita/b) = 1.
i.e. bx costhita + ay sinthita = ab.
CF= ab/sqrt (b^2 cos^2thita + a^2 sin^2thita).
Equation of Normal at 
P(a costhita, b sinthita) on ellipse is
ax/ costhita – by/ sinthita =a^2-b^2.
solving with y=0 we get G= ( (a^2-b^2) costhita /a, 0).
By distance formula, PG = (b/a)sqrt (b^2 cos^2thita + a^2 sin^2thita).
CF  PG = b^ 2
 

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

Other Related Questions on Magical Mathematics[Interesting Approach]

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More