Question

Difficulty: MediumFunction Evaluation, Composition, and Properties

The table below shows some values of the functions ff and gg for several integer values of xx.

xxf(x)f(x)g(x)g(x)
2-23311
1-1442-2
001-133
112200
222-21-1
331122

What is the value of f(f(3))+g(g(1))f(f(3)) + g(g(-1))?

Answer: 3

Answer

The value of the expression is 33.
To evaluate f(f(3))+g(g(1))f(f(3)) + g(g(-1)), we start by evaluating the innermost expressions. Looking at the table for x=3x = 3, we find f(3)=1f(3) = 1. Looking at the table for x=1x = -1, we find g(1)=2g(-1) = -2. Substituting these values into the outer functions gives f(1)+g(2)f(1) + g(-2). Using the table again, we look up x=1x = 1 to find f(1)=2f(1) = 2, and look up x=2x = -2 to find g(2)=1g(-2) = 1. Adding these two results yields 2+1=32 + 1 = 3.

Step-by-Step Solution

1
Find the inner function values from the given table.
f(3)=1f(3) = 1 and g(1)=2g(-1) = -2
Before evaluating the composite functions, we must find the outputs of the innermost functions.
2
Evaluate the outer functions using the results from the first step.
f(f(3))=f(1)=2f(f(3)) = f(1) = 2 and g(g(1))=g(2)=1g(g(-1)) = g(-2) = 1
Substitute the inner outputs into the outer functions and look up the new inputs in the table.
3
Add the two resulting values together.
2+1=32 + 1 = 3
Combine the two terms to find the total sum requested by the question.

Key Concept

Evaluating composite functions using tables of values
Estimated Time:1m 0s
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