Question 1035609
Let us divide everything by 16...
{{{16x^2 + 4y^2 = 16}}}
{{{x^2 + y^2/4 = 1}}}
This is an ellipse, taller than wide.
It's semi-major axis is 2 and semi-minor axis is 1.
Thus the domain is [-1, 1].
Its range is [-2, 2].