Understand the problem: Understand the problem.We need to find the value of the logarithm of 48 with base 7, which is written as log7(48).
Express as power of 7: Express 48 as a power of 7, if possible.48 is not an integer power of 7, so we cannot directly find an integer answer like in the previous example. We will need to use a calculator or logarithm properties to approximate the value or express it in terms of logarithms we know.
Use logarithm properties: Use logarithm properties to simplify the expression, if possible.Since 48 is not a power of 7, we cannot simplify log7(48) to an integer. However, we can use the change of base formula to express this logarithm in terms of natural logarithms (ln) or common logarithms (log), which are more easily calculated with a calculator.The change of base formula is: logb(a)=logc(b)logc(a), where c is a new base we choose.
Apply change of base: Apply the change of base formula.Let's use the natural logarithm (base e). We can rewrite log7(48) as ln(48)/ln(7).
Calculate with calculator: Calculate the value using a calculator.Using a calculator, we find:ln(48)≈3.8712ln(7)≈1.9459Now, divide ln(48) by ln(7) to get the value of log7(48).log7(48)≈1.94593.8712≈1.9890