Answer: {x, y ∈ R : y ≠ -2x²}
Step-by-step explanation:
 The domain of a function is all possible values of x and y that will make the function true. 
 The function given is: 
 

 This is a rational function. Here, we can see that the function is undefined when the denominator (y + 2x²) equals 0 since dividing by 0 is undefined.
 We can set the denominator (y + 2x²) equal to 0 and solve this equation for y:
 y + 2x² = 0
 y = -2x²
In mathematical notation, the domain can be expressed as follows:
 Domain = {x, y ∈ R : y ≠ -2x²}
 This shows that the domain consists of all real numbers where y is not equal to -2x², as these values would make the denominator of the function equal to zero (meaning the rational function is undefined).