SOLUTION: Graph 9x^2+y^2=9 Give the coordinates of the foci

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Question 188878: Graph 9x^2+y^2=9
Give the coordinates of the foci
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2%2By%5E2%2F9=1
:
c%5E2=9-1
:
c=(+-)sqrt(8)
:
c=(+-)2sqrt(2)
:
foci are at (0,+2sqrt(2)) and (0,-2sqrt(2))