Math Problem Statement

log_4(x^3) + log_2(sqrt(x)) = 8

Solution

The given equation is:

log4(x3)+log2(x)=8\log_4(x^3) + \log_2(\sqrt{x}) = 8

Step-by-step Solution:

  1. Simplify the logarithms:

    • Use the logarithm power rule: logb(an)=nlogb(a)\log_b(a^n) = n \cdot \log_b(a).
    • For log4(x3)\log_4(x^3): log4(x3)=3log4(x)\log_4(x^3) = 3 \cdot \log_4(x)
    • For log2(x)\log_2(\sqrt{x}), recall that x=x1/2\sqrt{x} = x^{1/2}, so: log2(x)=12log2(x)\log_2(\sqrt{x}) = \frac{1}{2} \cdot \log_2(x)

    Substituting these back into the equation: 3log4(x)+12log2(x)=83 \cdot \log_4(x) + \frac{1}{2} \cdot \log_2(x) = 8

  2. Convert log4(x)\log_4(x) to base 2: Using the base-change formula log4(x)=log2(x)log2(4)\log_4(x) = \frac{\log_2(x)}{\log_2(4)}, and knowing log2(4)=2\log_2(4) = 2, we have: log4(x)=log2(x)2\log_4(x) = \frac{\log_2(x)}{2} Substituting this into the equation: 3log2(x)2+12log2(x)=83 \cdot \frac{\log_2(x)}{2} + \frac{1}{2} \cdot \log_2(x) = 8

  3. Simplify the equation: Combine terms with log2(x)\log_2(x): 32log2(x)+12log2(x)=8\frac{3}{2} \cdot \log_2(x) + \frac{1}{2} \cdot \log_2(x) = 8 2log2(x)=82 \cdot \log_2(x) = 8

  4. Solve for log2(x)\log_2(x): Divide through by 2: log2(x)=4\log_2(x) = 4

  5. Solve for xx: Rewrite in exponential form: x=24=16x = 2^4 = 16

Final Answer:

x=16x = 16


Would you like further details or clarifications? Here are some related questions:

  1. How does the base-change formula for logarithms work?
  2. What are other rules of logarithms that simplify equations?
  3. Can you solve a similar equation with different bases?
  4. How does exponential growth relate to logarithms?
  5. What happens if the base of one logarithm is irrational?

Tip: Always rewrite logarithmic equations in a single base to simplify calculations.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Logarithms
Exponents
Algebra

Formulas

log_b(a^n) = n * log_b(a)
log_b(a) = log_c(a) / log_c(b)
sqrt(x) = x^(1/2)

Theorems

Logarithm Rules
Change of Base Formula

Suitable Grade Level

Grades 10-12