PSAT Math Multiple-Choice Question 409: Answer and Explanation

Question: 409

For the two functions f(x) and g (x), tables of values follow. What is the value of f (g(1))?

x	f(x)
-2	8
-1	6
0	4
1	2

x	g(x)
-1	-4
1	0
2	2
4	6

• A. 0
• B. 2
• C. 4
• D. 6

Correct Answer: C

Explanation:

C

Difficulty: Easy

Category: Function Notation

Getting to the Answer: This is a composition of functions, so start with the innermost set of parentheses, which is g(1). According to the g(x) table, when x = 1, g(x) = 0. Then, x = 0 becomes the input for f. Now, find f (0); the f(x) table shows this is equal to 4, which is (C).