to view the math menu.Graphing Math Menu
When a graph is displayed, press
to view the math menu.
to see more options. 
to select
Root which finds an x-intercept.
to select Maximum which finds a relative maximum.
to select Minimum which finds a relative minimum.
to select Y-intercept which finds the y-intercept of a curve.
to select Intersection which finds a point
of intersection. to select
y-calculate which finds a value of x for a given y. to select
x-calculate which evaluates the function for a given x. to select
which finds a
definite integral of a function.