Question

if an ellipitical whisperingn room has a height of 30 ft and a width of 100ft, where should two people stand if they would like to whisper back and forth and be hard.

Answer 1

So that basically is just asking what the foci of your ellipse are

Answer 2

At the focii

Answer 3

ok

Answer 4

I forget the formula for the foci, let me look it up

Answer 5

its A2-B2=C2

Answer 6

great, so what is the issue here?

Answer 7

umm welll so would i do 100-30

Answer 8

you understand that the formula is\[b^2-a^2=c^2\]so you have to square a and b...\[c=\sqrt{b^2-a^2}\]and the foci are\[(-c,0),(c,0)\]

Answer 9

nooo its a^2-b^2=C^2

Answer 10

depends on your major axis whether you add c to the x-coordinate of the center or y-coordinate

Answer 11

ohh ok

Answer 12

ok so was i right when i said 100-30=70

Answer 13

a^2 is not 100, b^2 is not 30

Answer 14

they gave you the width and height of the ellipse, not a and b

Answer 15

okkk so how do i find a and b thats my issue

Answer 16

They are half the width and height

Answer 17

50-15

Answer 18

i know that part

Answer 19

so for horizontal major axis, a>b
a = 1/2 width
b= 1/2 height

Answer 20

a=50
b=15

Answer 21

right

Answer 22

now c^2=a^2-b^2

Answer 23

solve for c, the focii are at (c,0) and (-c,0)

Answer 24

ok so 50^2-15^2

Answer 25

\[c=\sqrt{50^2-15^2}\]

Answer 26

50^2=2500
15^2=225
2275 square root of that is 47.69

Answer 27

\[5\sqrt{91} \approx 47.70\]

Answer 28

ok same thing so since we know the foci so should people stand 47ft. away in order for them to whisper back and forth

Answer 29

no, the focii are 47.7 ft from the center (0,0), so they'd stand twice as far away as 47.7, but be standing at the focii

Answer 30

person a would be standing at (5sqrt(91),0), person b would be standing at
(-5sqrt(91),0)

Answer 31

ohh ok so do you think i would have to graph this

Answer 32

|5sqrt(91)+5sqrt(91)|=10sqrt(91)

Answer 33

does it tell you to graph it?

Answer 34

i wouldn't

Answer 35

ohh okay tynkss soo ,muchh

Answer 36

np