Intersection of a 2D graph with the axis

• The ordinate of the intersection of the graph of f with the y-axis is returned by :
  f(0)
  indeed the point of coordinates (0, f (0)) is the intersection point of the graph of f with the y-axis,
• Finding the intersection of the graph of f with the x-axis requires to solve the equation f (x) = 0.
  If the equation is polynomial-like, solve will find the exact values of the abscissa of these points. Input:
  solve(f(x),x)
  Otherwise, we can find numeric approximations of these abscissa. First look at the graph for an initial guess or a range with an intersection and refine with fsolve.