e-Gor i need you again my friend :D

[Raymond.Reiloff]

q1. what are the focal points of and ellips with the equation x^2/14+y^2/5=1 ?

q2. what are the focal points of an ellips with major axis 2 along x-axis and minor axis 1 along the y-axis ?



now on this equation:

16a^2+8a(2c^2/4a)+(4c^4/4a^2)= (x-c)^2 +(y-0)^2

at what points does the ellips cut the x- and y-axis.this will give the length of the major and minor axis.
express the major and minor axis length's as term's of c and a

i know this is alot of stuf but if you can help me with something id be a happy camper...

i also hope its readable since i translated the questions myself

thanks in advance
T



if anyone else but e-Gor knows anything about this feel free to add in and get me off his back...

[[R-DEV]e-Gor]

Don't know much about conic geometry, so can't give you a solution without learning it all myself (even though I think I'm supposed to know it...) Look up ellipse on wikipedia or something. But here's a few quick comments that might (or might not) be useful:

q1: I notice that it's symmetric around the x and y axes - so both foci must be on one or other of the axes, the same difference from the origin. In this case it's stretched more along the x axis, so the foci would be at (a,0) and (-a,0), for some a...

q2: I assume with this you mean it has a centre of (2,1) with the major axis parallel to the x-axis and the minor parallel to the y-axis? In which case, surely you need more information to find the foci? Or am I not understanding the question?

q3: To find where it cuts the x axis, just set x = 0. Likewise for the y axis. Too lazy to type out the algebra at the moment...
Just something I noticed about the equation: taking out a factor of 1/a^2 you get a quadratic in (c/a)^2 which is usually going to be nicer to work with. No idea if that's useful or not though.
i.e. (1/a^2) ( 16 + 4(c/a)^2 + (c/a)^4 ) = (x-c)^2 + y^2

Sorry I can't be of much help this time...

[NiGHTWoLF]

.............what the f*ck

[trogdor1289]

nightwolf I do believe we are out of our depth.

[[R-DEV]Katarn]

This is basic geometry from.....9th grade? Seriously?

[[R-DEV]duckhunt]

Originally Posted by [R-DEV]Katarn

This is basic geometry from.....9th grade? Seriously?

you crack me up



.good luck, that sht looks intense

[EagleEyeLG]

Originally Posted by [R-DEV]duckhunt

you crack me up



.good luck, that sht looks intense

Well unless I'm just looking at it incorrectly, it looks like pre-calc or calc, maybe trig. Am I wrong?

[[R-DEV]e-Gor]

Originally Posted by [R-DEV]Katarn

This is basic geometry from.....9th grade? Seriously?

Depends where you are. It's not covered over here. But yeah, it's basic geometry.

[Thunder]

owww i love this stuff. i think i figured it out on paper. but im going let you solve it as its the best way to learn

[[R-DEV]e-Gor]

Originally Posted by [R-MOD]Thunder

owww i love this stuff. i think i figured it out on paper. but im going let you solve it as its the best way to learn

Woah, that's far too much effort to go to :P As far as learning goes, it's often best to give the general method, or hints, but not give the answer.

Personally, I hate geometry