Simplify \( \log_3 81 \) by expressing it using a change of base to base 10.
Upstudy AI Solution
Answer
Solution
Answered by UpStudy AI and reviewed by a Professional Tutor


The Deep Dive
To simplify \( \log_3 81 \) using a change of base to base 10, you can use the formula: \[ \log_b a = \frac{\log_k a}{\log_k b} \] In this case, \( a = 81 \), \( b = 3 \), and \( k = 10 \). So we have: \[ \log_3 81 = \frac{\log_{10} 81}{\log_{10} 3} \] Now, \( 81 \) can be expressed as \( 3^4 \), allowing us to compute \( \log_{10} 81 \): \[ \log_{10} 81 = \log_{10} (3^4) = 4 \cdot \log_{10} 3 \] Substituting this back into the change of base formula gives: \[ \log_3 81 = \frac{4 \cdot \log_{10} 3}{\log_{10} 3} = 4 \] Therefore, the simplified form of \( \log_3 81 \) is \( \boxed{4} \).