INTERSECT: Find intersections

syntax: INTERSECT(expr, varname, lower, upper) or
INTERSECT(expr1, expr2, varname, lower, upper)

find points of intersection between two functions of variable <varname> <expr1> and <expr2>, optionally a lower and upper bound within which the points of intersection is sought after can be specified. If the second function is omitted then points of intersection between the single function specified <expr> and the x = 0 line (x axis) is sought after, that is the function <expr> is equated to zero. The function returns the number of intersection points found. The coordinates of the intersection points themselves are stored in the file: mcalc_graph<session#>z where <session #> is substituted with the current session number for the calculator or 0 if not in asynchronous mode.