関連ワード:  is piecewise function a function    is piecewise function a type of function    is a piecewise function a rational function    is a piecewise function a polynomial function    is a piecewise function one function    is a step function a piecewise function    is absolute value function a piecewise function    how to tell if piecewise function is a function    why is a piecewise function called a piecewise function    what is piecewise function and example