Find the standard form of the equation of the ellipse with the following characteristics.
Foci: (+-3,0)
Major Axis of Length: 18

Question

Find the standard form of the equation of the ellipse with the following characteristics.
Foci: (+-3,0) 
Major Axis of Length: 18

anonymous · Answer

amistre64 · Answer

since the foci are along the x axis; we get:

x^2    y^2
--- + --- = 1  ; so far :)
r^2     r^2

amistre64 · Answer

i should rewrite that like this:

x^2    y^2
--- + --- = 1
a^2    b^2

amistre64 · Answer

a^2 - b^2 = c^2 ; where c = the distance from the center a foci; and a = the distance from the center to a vertex...in this case its 9 i believe

amistre64 · Answer

9^2 - 3^2 = b^2

81 - 8 = b^2

73 = b^2
81 = a^2

x^2    y^2
--- + --- = 1  i believe is the form
 81      73

anonymous · Answer

oh ok I see how you got that! Except it would be 72 not 73. Thanks

anonymous · Answer

I was close the first time I tried it.

amistre64 · Answer

lol.....3^2 doesnt = 8?   since when?

anonymous · Answer

lol it's al good I got the idea lol