Math Problem Statement

what is log base 4 (x^2-6x)=2

Solution

To solve the equation:

log4(x26x)=2\log_4(x^2 - 6x) = 2

Step 1: Rewrite the Logarithmic Equation in Exponential Form

The equation can be rewritten in exponential form as:

x26x=42x^2 - 6x = 4^2

since 42=164^2 = 16, this becomes:

x26x=16x^2 - 6x = 16

Step 2: Rearrange into a Standard Quadratic Equation

Move all terms to one side:

x26x16=0x^2 - 6x - 16 = 0

Step 3: Solve the Quadratic Equation

Now we factor the quadratic:

(x8)(x+2)=0(x - 8)(x + 2) = 0

Setting each factor equal to zero:

x8=0x=8x - 8 = 0 \Rightarrow x = 8 x+2=0x=2x + 2 = 0 \Rightarrow x = -2

Step 4: Check for Valid Solutions

Since we are dealing with a logarithmic function, the argument x26xx^2 - 6x must be positive.

  1. For x=8x = 8:
    x26x=8268=6448=16x^2 - 6x = 8^2 - 6 \cdot 8 = 64 - 48 = 16, which is positive.

  2. For x=2x = -2:
    x26x=(2)26(2)=4+12=16x^2 - 6x = (-2)^2 - 6 \cdot (-2) = 4 + 12 = 16, which is also positive.

Solution

Both values, x=8x = 8 and x=2x = -2, satisfy the original equation.

x=8 and x=2\boxed{x = 8 \text{ and } x = -2}

Would you like further explanation on logarithmic functions, or do you have any questions?


Related Questions:

  1. How do you solve logarithmic equations with different bases?
  2. What is the importance of checking domain constraints in logarithmic equations?
  3. How do you factor a quadratic equation if it doesn't factor nicely?
  4. What if the logarithmic function has a base different than an integer?
  5. How do you solve exponential equations?

Tip: Always check the argument of a logarithmic function to ensure it stays positive for real solutions.

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Math Problem Analysis

Mathematical Concepts

Logarithms
Exponential Form
Quadratic Equations

Formulas

log_b(a) = c implies b^c = a
Quadratic equation ax^2 + bx + c = 0

Theorems

Properties of Logarithms
Quadratic Formula

Suitable Grade Level

Grades 9-12