Rational Functions: Solving Rational Equations and Inequalities

Estimating the Value of a Function Given a Graph

You may also be given the graph of a rational function and asked to estimate a value of f(x) given a value of x.

For example, given the following graph, estimate the value of f(x) if x = -3.

Graph of f(x) equals the quantity x plus one divided by the quantity x minus one.
f of x equals the quantity x plus 1 divided by the quantity x minus 1

If you look at the value of x = -3 on the graph you will see that the f(-3) value is approximately 0.5.