Determine whether each equation defines y as a function of x.
2x + y2 = 6

NOT a function

Step-by-step explanation:

y^2 (not y2) is "the square of y"

The given 2x + y^2 = 6 can be solved for y as follows:

Subtracting 2x from both sides, we get     y^2 = 6 - 2x, whose y-values are y = ±√(6 - 2x).  Because there are two y-values associated with each x value, this is NOT a function.  In a function there is only one y value for each x value.