Answer:
1. Non - linear
2. Linear
3. Linear
4. Linear
Explanation:
All linear equations can be expressed in the form of
where m is slope and b is y-intercept.
Horizontal line is a special case of linear functions, where slope is 0. It means y=b is also a linear funcion.
First function is
It is a non linear function.
Second function is
It is a linear function.
Third function is
It is a linear function.
Fourth function is
It is a linear function.