- Evaluating a function means finding the value of the function that corresponds to a given input value of .
- The process of evaluating a function is described in the following two steps mentioned below:
- Replace the input variable with the provided value
- Simplify the expression to get the final result
- Sometimes a function can also be expressed in tabular form or graphical form. We find the output value in such cases by looking at the table or graph.
Question 1: Given , find the value of .
Question 2: Based on the table below, find the value of .
Solution: From the given table, we get .
Question 3: Find from the graph shown below.
Solution: From the given graph, we get .
- To evaluate a function at a given input, we substitute the variable in the function with the given input value and then simplify it to get the final result.
- It is recommended to put the substituted values inside parentheses in order to avoid committing mistakes.
- Note that .