Answer
$\{(0,-1),(0,1)\}$
Work Step by Step
$x^{2}+y^{2}=1$
is a circle, centered at the origin, radius 1.
$ x^{2}+9y^{2}=9\qquad/\div9$
$\displaystyle \frac{x^{2}}{9}+\frac{y^{2}}{1}=1$,
is an ellipse, horizontal major axis,
center: origin
a=3, b=1
Intersection points:
$\{(0,-1),(0,1)\}$.
