A function is a relationship between two variables that satsifes the condition that there is one and only one value of the image (the dependent variable) for each value of the domain (the set of values of the independent variable).
All the set of values of the image are what is called the range.
1) It is a function, as there is one and only one value of y for each value of x.
The domain, the set of values that x can take, is all the real numbers.
The range, instead, only takes values above y=-3.
Answer:
Function: Yes
Domain: All real numbers
Range: y>=-3.
2) It is a function, as there is one and only one value of y for each value of x.
The domain, the set of values that x can take, is all the real numbers.
The range is also all the real numbers, as the arrows indicate no limit for the values that the function can take.
Answer:
Function: Yes
Domain: All real numbers
Range: All real numbers
3) It is a function, as there is one and only one value of y for each value of x.
The function is defined for values of x that are bigger or equal than -3, so the domain is x>=-3.
The values that the function takes are equal or bigger than 0, so the range is y>=0.
Answer:
Function: Yes
Domain: x >= -3
Range: y >= 0