Exercises: Evaluate the following limits by constructing the table of values. ( 5 points each item) (Show step by step process on your answer sheet) 1. \( \lim _{x \rightarrow 2} 5^{x} \) 2. \( \lim _{x \rightarrow 4} \log x \) 3. \( \lim _{x \rightarrow \pi} \cos x \)
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To evaluate the given limits using tables of values, we will create a systematic approach to observe the behavior of each function as \( x \) approaches the specified values. ### 1. \( \lim _{x \rightarrow 2} 5^{x} \) **Step 1:** Choose values around \( x = 2 \). For example, we can choose \( x = 1.9, 1.95, 1.99, 2.01, 2.05, 2.1 \). **Step 2:** Calculate \( 5^{x} \) for each value: - \( x = 1.9 \) → \( 5^{1.9} \approx 4.57 \) - \( x = 1.95 \) → \( 5^{1.95} \approx 4.87 \) - \( x = 1.99 \) → \( 5^{1.99} \approx 4.99 \) - \( x = 2.01 \) → \( 5^{2.01} \approx 5.01 \) - \( x = 2.05 \) → \( 5^{2.05} \approx 5.16 \) - \( x = 2.1 \) → \( 5^{2.1} \approx 5.25 \) **Step 3:** Create the table: | \( x \) | \( 5^{x} \) | |----------|----------------| | 1.9 | 4.57 | | 1.95 | 4.87 | | 1.99 | 4.99 | | 2.01 | 5.01 | | 2.05 | 5.16 | | 2.1 | 5.25 | **Conclusion:** As \( x \) approaches 2, \( 5^{x} \) approaches \( 5 \). Therefore, \( \lim_{x \to 2} 5^{x} = 5 \). ### 2. \( \lim _{x \rightarrow 4} \log x \) **Step 1:** Choose values around \( x = 4 \): \( x = 3.9, 3.95, 3.99, 4.01, 4.05, 4.1 \). **Step 2:** Calculate \( \log x \) for each value (using base 10 for simplicity): - \( x = 3.9 \) → \( \log(3.9) \approx 0.591 \) - \( x = 3.95 \) → \( \log(3.95) \approx 0.597 \) - \( x = 3.99 \) → \( \log(3.99) \approx 0.602 \) - \( x = 4.01 \) → \( \log(4.01) \approx 0.604 \) - \( x = 4.05 \) → \( \log(4.05) \approx 0.607 \) - \( x = 4.1 \) → \( \log(4.1) \approx 0.613 \) **Step 3:** Create the table: | \( x \) | \( \log x \) | |----------|----------------| | 3.9 | 0.591 | | 3.95 | 0.597 | | 3.99 | 0.602 | | 4.01 | 0.604 | | 4.05 | 0.607 | | 4.1 | 0.613 | **Conclusion:** As \( x \) approaches 4, \( \log x \) approaches \( \log(4) \approx 0.602 \). Therefore, \( \lim_{x \to 4} \log x = \log(4) \). ### 3. \( \lim _{x \rightarrow \pi} \cos x \) **Step 1:** Choose values around \( x = \pi \): \( x = 3.13, 3.14, 3.15, 3.16, 3.17, 3.18 \). **Step 2:** Calculate \( \cos x \) for each value: - \( x = 3.13 \) → \( \cos(3.13) \approx -0.999 \) - \( x = 3.14 \) → \( \cos(3.14) \approx -1 \