Given log53 = 0.6826 and log58=1.2920, evaluate the expressions.
(a) log52
(b) log5(75/8)
Thank you so much for checking this question out, can you please help me solve it
Simply use some creative algebraic manipulation with the property of logarithms to find an approximation for the other expressions.
a) \(\log_{5}2\)
There are probably many approaches that would lead to the same answer, but here is how I would approach this one:
\(\log_{5}8 =\log_{5}2^3 \\ \log_58 = 3\log_52 \\ 1.2920 = 3\log_52 \\ \log_52 = \frac{1.2920}{3} \approx 0.4307\)
b) \(\log_5 \frac{75}{8}\)
Luckily, we use the result from before to help this particular problem.
\(\log_5 \frac{75}{8} = \log_5 75-\log_5 8 \\ \log_5 \frac{75}{8} = \log_5 (3*25) - \log_5 8\\ \log_5 \frac{75}{8} = \log_5 3 + \log_5 25 - \log_5 8\\ \log_5 \frac{75}{8} = 0.6826 + 2 - 1.2920 \approx 1.3906 \\ \)
You can check to determine if your answer is reasonable by using a calculator and evaluating \(\log_5 2\) and \(\log_5 \frac{75}{8}\). The decimal expansion should be match up for the first few digits.
Simply use some creative algebraic manipulation with the property of logarithms to find an approximation for the other expressions.
a) \(\log_{5}2\)
There are probably many approaches that would lead to the same answer, but here is how I would approach this one:
\(\log_{5}8 =\log_{5}2^3 \\ \log_58 = 3\log_52 \\ 1.2920 = 3\log_52 \\ \log_52 = \frac{1.2920}{3} \approx 0.4307\)
b) \(\log_5 \frac{75}{8}\)
Luckily, we use the result from before to help this particular problem.
\(\log_5 \frac{75}{8} = \log_5 75-\log_5 8 \\ \log_5 \frac{75}{8} = \log_5 (3*25) - \log_5 8\\ \log_5 \frac{75}{8} = \log_5 3 + \log_5 25 - \log_5 8\\ \log_5 \frac{75}{8} = 0.6826 + 2 - 1.2920 \approx 1.3906 \\ \)
You can check to determine if your answer is reasonable by using a calculator and evaluating \(\log_5 2\) and \(\log_5 \frac{75}{8}\). The decimal expansion should be match up for the first few digits.