Question

What are the foci of the following graph?
(graph and answers will be attached)

Answer 1

@dan815

Answer 2

@SolomonZelman

Answer 3

@TheSmartOne

Answer 4

@timbo5lice how about this one? thanks

Answer 5

@TheSmartOne

Answer 6

@phi

Answer 7

what are the lengths of the semi-major and semi-minor axes?

Answer 8

6 and 3@phi

Answer 9

6 for major and 3 for minor @phi

Answer 10

now find the difference of their squares, i.e. 6*6 - 3*3

Answer 11

27 squared @phi

Answer 12

now take the square root. that will be the distance along the major axis from the center to the focus

Answer 13

the center is at (0,0)

Answer 14

@phi so the answer is B

Answer 15

yes, the major axis is the y-axis (so x=0)
the two focuses are at y = 0+ sqr(27) and 0 - sqr(27)
or
(0, sqr(27)) and (0, -sqr(27))

Answer 16

@phi for this one i tried to solve it and i chose C as the correct answer. am i correct

Answer 17

yes. same problem, with nicer numbers (and the major axis is sideways)

Answer 18

thank you. @phi

Answer 19

@phi