Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Conic Sections
Hotmath provides 26 practice problems relating to conic sections. Each of the practice problems include a step-by-step guide for solving their conic.
Math Is Fun
Math Is Fun: Conic Sections
Students learn about conic sections. Topics include eccentricity, directrix, and the general equation. The tutorial consists of notes, examples, and practice problems to check for comprehension.
Mathematics Archives
Math Archives: Eccentricity in Polar Conics
Good site explaining Eccentricity in Polar Conics. The site is quite detailed.