Question

I need help with conics... how do I graph

(x^2)/4 + (y^2)/9 = 1

Answer 1

it is an ellipse centred at the origin

Answer 2

its major axis lies along the y-axis, and has length 6, 3 units on both sides of origin

Answer 3

its minor axis is along the x-axis, wth length 4

Answer 4

what do you use the 4 and 9 for?

Answer 5

see 9 is the b^2 ..now as b^2 > a^2, the major axis is along the y-axis

Answer 6

the length of the major axis is 2 * 3

Answer 7

3 is the sqrt of 9

Answer 8

it says i need to graph the answer, can you walk me through the steps on how to graph it?

Answer 9

do u know how to draw an ellipse?

Answer 10

yes, we did this a while ago, but i forgot how to do it all!

Answer 11

its like a circle elongated along one axis, remember?

Answer 12

yea!

Answer 13

so now remember a vertical ellipse

Answer 14

like this maybe?

Answer 15

see an elipse is shown by

(x/a)^2 + (y/b)^2 = 1

Answer 16

okay, then what

Answer 17

now generally the length of the major axis , ie, the axis along which it its elongated, is 2a

Answer 18

but ur case is not the general one .here b is greater than a

Answer 19

so its vertical?

Answer 20

so instead of being horizontally elongated, its vertically elongated..bingo..

Answer 21

okay, i see, so then the points would be, (0,3), (0, -3), (2,0), (-2,0)
is that correct?

Answer 22

yes maam

Answer 23

awesome thank you! can you help me with another problem?

Answer 24

sure

Answer 25

I need to find the foci of\[x^{2}/ 9 + y ^{2} / 36 = 1\]

Answer 26

= sorry

Answer 27

now the points are (0.6) (0,-6) and (3,0) (-3,0)

Answer 28

wait why does y egual 4x