Use the power property to rewrite log₃(9).
The Correct Answer and Explanation is:
Final Answer:
log3(9)=log3(32)=2\log_3(9) = \log_3(3^2) = 2
Explanation
To simplify log3(9)\log_3(9) using the power property of logarithms, we first need to express 9 as a power of the base 3.
Step 1: Express the number as a power of the base
Notice that: 9=329 = 3^2
So, we rewrite the logarithm: log3(9)=log3(32)\log_3(9) = \log_3(3^2)
Step 2: Apply the power property of logarithms
The power property states that: logb(an)=n⋅logb(a)\log_b(a^n) = n \cdot \log_b(a)
Here, a=3a = 3, n=2n = 2, and b=3b = 3. Applying the rule: log3(32)=2⋅log3(3)\log_3(3^2) = 2 \cdot \log_3(3)
Step 3: Simplify using the identity logb(b)=1\log_b(b) = 1
log3(3)=1\log_3(3) = 1
So: 2⋅log3(3)=2⋅1=22 \cdot \log_3(3) = 2 \cdot 1 = 2
Thus, log3(9)=2\log_3(9) = 2
Why This Works:
Logarithms are the inverse of exponents. That means: logb(a)=cmeansbc=a\log_b(a) = c \quad \text{means} \quad b^c = a
In this problem: log3(9)=xmeans3x=9\log_3(9) = x \quad \text{means} \quad 3^x = 9
Since 32=93^2 = 9, then x=2x = 2. So the logarithm equals 2.
Using the power property helps us simplify logarithms by pulling exponents down as multipliers. This is especially useful when the argument inside the logarithm is a perfect power of the base.
This rule is commonly used in algebra and calculus to simplify expressions, solve exponential equations, or differentiate logarithmic functions.
