The notation of bivariate function is represented as*x=fa(x,y)z=fab(x,y)f=az(x,y)z=f(x,y)

The notation of a bivariate function is typically represented as f(x, y). This means that the function f is dependent on two variables, x and y.

Here's a step-by-step breakdown:

1. "x=fa(x,y)": This seems to suggest a function a that takes in two variables x and y and outputs x. However, this is a bit confusing because the output is the same as one of the inputs. It might be a typo or a specific case in a certain context.

2. "z=fab(x,y)": This could be interpreted as a function named 'fab' that takes in two variables, x and y, and outputs z.

3. "f=az(x,y)": This could be a function named 'az' that takes in two variables, x and y, and the output is assigned to f.

4. "z=f(x,y)": This is the standard notation for a bivariate function. The function f takes in two variables, x and y, and outputs z.

Please note that the specific meanings could vary based on the context in which they're used.