A Scaled-Ellipse Area Maximum

Problem

In the coordinate plane xOyxOy, the ellipse C:x2a2+y2b2=1C:\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1 (a>b>0a>b>0) has eccentricity 32\dfrac{\sqrt 3}2 and left and right foci F1F_1, F2F_2. The circle of radius 33 centered at F1F_1 and the circle of radius 11 centered at F2F_2 intersect, and their intersection point lies on the ellipse CC.

1. Find the equation of the ellipse CC. 2. Let E:x24a2+y24b2=1E:\dfrac{x^2}{4a^2}+\dfrac{y^2}{4b^2}=1. Let PP be any point on CC; a line y=kx+my=kx+m through PP meets EE at points AA and BB, and the ray POPO meets EE at a point QQ. (a) Find OQOP\dfrac{|OQ|}{|OP|}. (b) Find the maximum area of ABQ\triangle ABQ.

Answer

Solution

Difficulty8/10
TopicsExtrema, Affine Transformation, conic sections

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