Question

Is the following graph a function? Please justify your answer

Answer 1

No it is not a function. I did the vertical line test and 2 x's come up for 1 y. In fact any sideways parabola is not a function. It looks like if I was to write an equation \[y = \pm \sqrt{x} \pm 1, y = \sqrt{x}+1, y = -\sqrt{x} -1\]