Math Problem Statement

Solve the exponential equation e^(x^2 - 6) = e^(x - 5) algebraically. Approximate the result to three decimal places.

Solution

The equation in the image is:

ex26=ex5e^{x^2 - 6} = e^{x - 5}

Step-by-Step Solution:

  1. Simplify the equation: Since both sides have the base ee, set the exponents equal to each other: x26=x5x^2 - 6 = x - 5

  2. Rearrange into a standard quadratic form: Subtract xx and add 5 to both sides: x2x1=0x^2 - x - 1 = 0

  3. Solve the quadratic equation: Use the quadratic formula: x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} Here, a=1a = 1, b=1b = -1, and c=1c = -1. Substituting: x=(1)±(1)24(1)(1)2(1)x = \frac{-(-1) \pm \sqrt{(-1)^2 - 4(1)(-1)}}{2(1)} x=1±1+42x = \frac{1 \pm \sqrt{1 + 4}}{2} x=1±52x = \frac{1 \pm \sqrt{5}}{2}

  4. Approximate the solutions: x=1+521.618x = \frac{1 + \sqrt{5}}{2} \approx 1.618 x=1520.618x = \frac{1 - \sqrt{5}}{2} \approx -0.618

  5. Verify the solutions: Substitute x=1.618x = 1.618 and x=0.618x = -0.618 back into the original equation. Only the positive solution x=1.618x = 1.618 satisfies the equation since ex26e^{x^2 - 6} and ex5e^{x - 5} must be positive and comparable.

Final Answer:

x1.618x \approx 1.618

Would you like further clarification or help with another example? Here are some follow-up questions to consider:

  1. What does the quadratic formula calculate, and how is it derived?
  2. Can all exponential equations be solved by equating exponents?
  3. How can you verify if your solution to a quadratic equation is correct?
  4. Why is x=0.618x = -0.618 not valid in this specific case?
  5. How is the base ee used in exponential growth and decay problems?

Tip: Always double-check your solutions by substituting them back into the original equation to avoid errors.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Exponential Equations
Quadratic Equations
Algebra

Formulas

Quadratic equation formula: x = (-b ± √(b² - 4ac)) / 2a

Theorems

Exponential Equality Rule: If e^a = e^b, then a = b

Suitable Grade Level

Grades 10-12