A community for students. Sign up today!
Here's the question you clicked on:
 0 viewing
 2 years ago
The equation for an ellipse is \[\frac{ x ^{2} }{ a ^{2} }+\frac{ y ^{2} }{ b ^{2}}=1\] and the foci is given by (c,0) where \[c ^{2}=a ^{2}b ^{2}\] and my question is if b>a is the foci given by (0,c) where \[c ^{2}=a ^{2}b ^{2}\]
 2 years ago
The equation for an ellipse is \[\frac{ x ^{2} }{ a ^{2} }+\frac{ y ^{2} }{ b ^{2}}=1\] and the foci is given by (c,0) where \[c ^{2}=a ^{2}b ^{2}\] and my question is if b>a is the foci given by (0,c) where \[c ^{2}=a ^{2}b ^{2}\]

This Question is Closed

asnaseer
 2 years ago
Best ResponseYou've already chosen the best response.1yes, if a>b then foci are at \((\pm c, 0)\) otherwise they are at \((0, \pm c)\). see here for more details: http://hotmath.com/hotmath_help/topics/ellipse.html

henpen
 2 years ago
Best ResponseYou've already chosen the best response.0I suppose you could try to derive the equation as a locus from the two foci (c,0) and (c,0).dw:1354462354704:dw \[\sqrt{y^2+(xc)^2}+\sqrt{y^2+(x+c)^2}=k\]

Chlorophyll
 2 years ago
Best ResponseYou've already chosen the best response.0It seems you're confused with the notation: Foci always belong to major axis, and major axis always named a!

henpen
 2 years ago
Best ResponseYou've already chosen the best response.0\[y^2+(xc)^2+y^2+(x+c)^2+\sqrt{y^2+(xc)^2}\sqrt{y^2+(x+c)^2}=k^2\] \[y^2+(xc)^2+y^2+(x+c)^2k^2=\sqrt{y^2+(xc)^2}\sqrt{y^2+(x+c)^2}\] \[(y^2+(xc)^2+y^2+(x+c)^2k^2)^2=(y^2+(xc)^2)(y^2+(x+c)^2)\]ans so on

frx
 2 years ago
Best ResponseYou've already chosen the best response.0So thats the deal when a>b, right?

frx
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1354462661891:dw And that b>a

frx
 2 years ago
Best ResponseYou've already chosen the best response.0oh wrong it should be rotated 90 degrees

asnaseer
 2 years ago
Best ResponseYou've already chosen the best response.1yes, 'a' always represents the "major axis"
Ask your own question
Ask a QuestionFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.