How do you find the eccentricity, directrix, focus and classify the conic section r=2/(1+2costheta)r=21+2cosθ?

1 Answer
Jun 16, 2018

Eccentricity is 22, Focus is at the pole (0,pi/2)(0,π2),
Directrix is p=1p=1 unit at right from the pole.
Conic: Hyperbola

Explanation:

r= 2/(1+2 cos thetar=21+2cosθ .The equation is in the form

r= (ep) /(1+e cos theta) ; e =2r=ep1+ecosθ;e=2 since e >1e>1 the conic

is hyperbola. r= (ep) /(1+e cos theta) ; e p =2 :. p=1

Directrix is at p=1 unit at right from the pole.

Eccentricity is 2 , Focus is at the pole (0,pi/2) [Ans]