### Working with Functions

The math part of the test will have several questions on functions. Learn how to solve function questions with our free exercises.

Now try the following question on functions.

### Functions – Sample Question

Table of values for the functions f_{1}(*x*) and f_{2}(*x*) are given below.

What is the value of f_{2}(f_{1}(1))?

x |
f_{1}(x) |
x |
f_{2}(x) |

1 | 4 | 1 | 1 |

2 | 5 | 2 | 4 |

3 | 6 | 3 | 9 |

4 | 7 | 4 | 16 |

A. 1

B. 4

C. 7

D. 9

E. 16

**The correct answer is E.**

Function problems will often include a table like the one provided above.

In order to solve the function, you need to look at the corresponding value in the table.

So, for example, the value of f_{1}(2) from the table above is 5.

To solve the problem, you just have to look at the row for the number 2 and find the value in the second column of the table for f_{1}.

So first of all, solve for the function in the inner-most set of parentheses, which in this problem is *f*_{1}(1).

According to the table of values at the left above, for *x* = 1, *f*_{1}(1) = 4

Then, take this new value to solve for *f*_{2}(*x*)

According to the table of values at the right above, for *x* = 4, *f*_{2}(4) = 16