From this pic we can conclude it is function composite of the following parent functions:
The face is a circle, the parent function is:

The same for the eyes, the smile can be described using a parabola of the form:

The vertical line of the body can be described as:

The arms can be described using a cosine function:

Finally the legs can be describe using linear equations, one of them has a positive slope and the other one has a negative slope:

Finally from the graph the largest y value and the smallest y value are:
