• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

conics... (1 Viewer)

CriminalCrab

Member
Joined
Mar 14, 2011
Messages
32
Gender
Undisclosed
HSC
2012
1. Find the equation of the ellipse with centre the origin and foci at points (-5root3,0) and (5root3,0), given that it passes through the point (8,3)
Ans:x^2 +4y^2=100

2. P is the point (acostheta,bsintheta) on the ellipse E: [general form of ellipse eqn] with eccentricity e and foci S,S'. Show that SP=a(1-ecostheta) and find an expression for S'P. Hence prove that the sum of the focal distances PS,PS' is independent of the position of P on the ellipse.

Thanks in advance, maths nerds.
enjoying holidays? =)
 

Carrotsticks

Retired
Joined
Jun 29, 2009
Messages
9,494
Gender
Undisclosed
HSC
N/A
Here is the solution to the first part.

I need to head off soon, but I'll do the second part once I come back (assuming nobody else has already done it for me):



 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top