Example OW.ICPPF.3 : $InvP_4(x)=+\sqrt[4] x$.
    Draw a mapping diagram and graph of $InvP_4$ yourself,    or consider the GeoGebra figures and table below.
    
  
    
Martin Flashman, Nov. 9, 2013,
        Created with GeoGebra
    
 
    The  GeoGebra figure illustrates the key property for an
    inverse: $(P_4^{-1} \circ P_4 )(x) =x$ for all $ x \in [0,\infty)$
    Notice how the points on the graph are paired with the points on the
    mapping diagram.
    Given a point / number, $x$, on the source line, there is a unique
    arrow  meeting the first target line at the point / number,
    $P_4(x)=x^4$, and  another arrow from the first target line to
    the point on the second target line  $P_4^{-1}
    (P_4(x))=+\sqrt[4] {x^4} = x $. which corresponds to the inverse
    core function's value for $P_4(x)$.
    Check the box in GeoGebra to see more points and arrows
    corresponding to data on the table.
    When the point in the domain is $0$, the arrow points to $P_4^{-1}
    (0) =  0$ visualizing the "Y-intercept" on the graph of
    $P_4^{-1} $. 
    This is the unique X- intercept as well. 
    The function is  increasing for all $x \in (0,\infty)$. 
    You can check this by moving $x$ on the GeoGebra mapping diagram.