Question

Help with ellipses

Answer 1

For the following equation, find the foci of the ellipse: \[\frac{ x^2 }{ 28 } + \frac{ y^2 }{ 64 }=1\]

Answer 2

a= sqrt28 b = 8

c=sqrt (sqrt28^2 - 8^2)
c=sqrt(28-64)
c=sqrt-36

@phi Could you explain what i did wrong :/

Answer 3

a= what ??

Answer 4

a is always going to be bigger number :-)
and that's what yo udid wrong :(

Answer 5

Ohhh This is one where its opposite the major axis length is 64

Answer 6

because its bigger

Answer 7

yes right bigger number is under y
and that's why it's vertical major axis

Answer 8

as you can see formula is
c^2 = a^2 - b^2
now a must be BIGGER number otherwise you would get a negative answer
does it make sense

Answer 9

so c^2= 8^2-sqrt28^2

Answer 10

64-28=36
c=sqrt36
c=6

Answer 11

yeah this one is right ^^

Answer 12

\(\color{blue}{\text{Originally Posted by}}\) @DarkBlueChocobo
so c^2= 8^2-sqrt28^2
\(\color{blue}{\text{End of Quote}}\)
a and b is already squared so no need to do it again :-)

Answer 13

So I have one question is this a vertical major axis?

Answer 14

if bigger number is under y then yes
if bigger number is under x then vertical

Answer 15

Hm do you mean

if bigger number is under x then horizontal ?

Answer 16

yeah yeah :P

Answer 17

\(\color{blue}{\text{Originally Posted by}}\) @Nnesha
if bigger number is under y then vertical
if bigger number is under x then vertical
\(\color{blue}{\text{End of Quote}}\)
if bigger number is under x then horizontal

Answer 18

so what's foci ?

Answer 19

(h, k + c), (h, k − c)

(0,0 + 6), (0,0-6)
(0,6), (0,-6)?

Answer 20

:-)

Answer 21

Thank you for the assistance :D

Answer 22

my pleasure
gO_Od job!!!