Question

Write the equation in standard form of the circle with the given properties.
Center at the origin; r = square root of 2

answer r= square root 2

Answer 1

or is this the correct answer x^2+y^2=2

Answer 2

oddly enough, both answers are correct!
in rectangular coordinates, x^2+y^2 = 2
in polar coordinates, r=√2
(but something tells me you have not yet studied polar coordinates -- you'll like them.)