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Exercises 4.3 Practice Problems

1.

Suppose \(f(x) = 2x+1\text{.}\)
Evaluate each of the following:
  1. \(\displaystyle f^{-1}(0)\)
  2. \(\displaystyle f^{-1}(4)\)
  3. \(\displaystyle f^{-1}(9)\)
  4. \(\displaystyle f^{-1}(1)\)
  5. \(\displaystyle f^{-1}(10)\)
Answer.
  1. \(\displaystyle f^{-1}(0)=\frac{-1}{2}\)
  2. \(\displaystyle f^{-1}(4)=\frac{3}{2}\)
  3. \(\displaystyle f^{-1}(9)=4\)
  4. \(\displaystyle f^{-1}(1)=0\)
  5. \(\displaystyle f^{-1}(10)=\frac{9}{2}\)

2.

Suppose \(f(x) = 3x-2\text{.}\)
Evaluate each of the following:
  1. \(\displaystyle f^{-1}(1)\)
  2. \(\displaystyle f^{-1}(3)\)
  3. \(\displaystyle f^{-1}(0)\)
  4. \(\displaystyle f^{-1}(5)\)
  5. \(\displaystyle f^{-1}(4)\)
Answer.
  1. \(\displaystyle f^{-1}(1)=1\)
  2. \(\displaystyle f^{-1}(3)=\frac{5}{3}\)
  3. \(\displaystyle f^{-1}(0)=\frac{2}{3}\)
  4. \(\displaystyle f^{-1}(5)=\frac{7}{3}\)
  5. \(\displaystyle f^{-1}(4)=2\)

3.

Suppose \(f(x)\) is given in the graph below.
Evaluate each of the following:
  1. \(\displaystyle f^{-1}(0)\)
  2. \(\displaystyle f^{-1}(1)\)
  3. \(\displaystyle f^{-1}(9)\)
  4. \(\displaystyle f^{-1}(2)\)
  5. \(\displaystyle f^{-1}(4)\)
Answer.
  1. \(\displaystyle f^{-1}(0)=1\)
  2. \(\displaystyle f^{-1}(1)=2\)
  3. \(\displaystyle f^{-1}(9)=5\)
  4. \(\displaystyle f^{-1}(2)=3\)
  5. \(\displaystyle f^{-1}(4)=4\)

4.

Suppose \(g(x)\) is given in the table below.
Table 4.3.1.
\(x\) \(-1\) \(3\) \(2\) \(5\) \(4\)
\(g(x)\) \(0\) \(3\) \(7\) \(1\) \(2\)
Evaluate each of the following:
  1. \(\displaystyle g^{-1}(0)\)
  2. \(\displaystyle g^{-1}(1)\)
  3. \(\displaystyle g^{-1}(3)\)
  4. \(\displaystyle g^{-1}(7)\)
  5. \(\displaystyle g^{-1}(2)\)
Answer.
  1. \(\displaystyle g^{-1}(0)=-1\)
  2. \(\displaystyle g^{-1}(1)=5\)
  3. \(\displaystyle g^{-1}(3)=3\)
  4. \(\displaystyle g^{-1}(7)=2\)
  5. \(\displaystyle g^{-1}(2)=4\)

5.

Suppose \(g(x)\) is given in the table below.
Table 4.3.2.
\(x\) \(0\) \(2\) \(3\) \(5\) \(4\)
\(g(x)\) \(0\) \(1\) \(7\) \(5\) \(2\)
Evaluate each of the following:
  1. \(\displaystyle g^{-1}(0)\)
  2. \(\displaystyle g^{-1}(1)\)
  3. \(\displaystyle g^{-1}(2)\)
  4. \(\displaystyle g^{-1}(7)\)
  5. \(\displaystyle g^{-1}(5)\)
Answer.
  1. \(\displaystyle g^{-1}(0)=0\)
  2. \(\displaystyle g^{-1}(1)=2\)
  3. \(\displaystyle g^{-1}(2)=4\)
  4. \(\displaystyle g^{-1}(7)=3\)
  5. \(\displaystyle g^{-1}(5)=5\)