** suivant:** Graph of inequations with
** monter:** Graph of a line
** précédent:** Tangent to a 2D
** Table des matières**
** Index**

##

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`.

giac documentation written by Renée De Graeve and Bernard Parisse