A certain treatment for kidney stones utilizes a water tank in the shape of one of the conic sections. The patient is placed in the tank with the kidney stones at one of the foci and a high-energy source at the other foci. The sum of the distances from the side of the tank to each focus is always constant. What is the shape of the water tank?
a. Circle
b. Ellipse
c. Parabola
d. Hyperbola

Question

A certain treatment for kidney stones utilizes a water tank in the shape of one of the conic sections.  The patient is placed in the tank with the kidney stones at one of the foci and a high-energy source at the other foci.  The sum of the distances from the side of the tank to each focus is always constant.  What is the shape of the water tank?
a.	Circle
b.	Ellipse
c.	Parabola
d.	Hyperbola

anonymous · Answer

What is a foci?

anonymous · Answer

Anyway, I think the answer is circle.

anonymous · Answer

i think its a ellipse

anonymous · Answer

a foci is are a pair of points used in determining conic sections

anonymous · Answer

But the sum of distances from the side of the tank to each focus is always constant.

anonymous · Answer

@tyler1992 why do you think it is a ellipse?

anonymous · Answer

Because i think ellipse's are the only conic section to have 2 foci's.. (not logical but its my thinking lol)

anonymous · Answer

maybe....

anonymous · Answer

http://www.mathwarehouse.com/ellipse/focus-of-ellipse.php