For which value(s) of do the graphs of the functions:
have only one point in common.
In order to calculate the intersection points of and we have to solve the following equation:
in the equation we get:
This quadratic equation has two coinciding solutions if the discriminant , so if:
If we get , i.e. and this does not give a solution. Thus the value of for which both graphs have just one common point is .
Verify that the common point is , see the figure.