Questions: Quiz
Solve the following equation for x.
e^(x^2-4x)=e^12
x=
(Type an integer or a decimal. Use a comma to
Transcript text: Quiz
Solve the following equation for x .
\[
\begin{array}{l}
e^{x^{2}-4 x}=e^{12} \\
x=\square
\end{array}
\]
(Type an integer or a decimal. Use a comma to
Solution
Solution Steps
To solve the equation \( e^{x^2 - 4x} = e^{12} \), we can take the natural logarithm of both sides to simplify the equation. This will allow us to solve for \( x \) by setting the exponents equal to each other and solving the resulting quadratic equation.
Solution Approach
Take the natural logarithm of both sides of the equation.
Set the exponents equal to each other.
Solve the resulting quadratic equation for \( x \).
Step 1: Take the Natural Logarithm of Both Sides
Given the equation:
\[
e^{x^2 - 4x} = e^{12}
\]
we take the natural logarithm of both sides:
\[
\ln(e^{x^2 - 4x}) = \ln(e^{12})
\]
Step 2: Simplify the Equation
Using the property of logarithms \(\ln(e^y) = y\), we simplify:
\[
x^2 - 4x = 12
\]
Step 3: Solve the Quadratic Equation
Rearrange the equation to standard quadratic form:
\[
x^2 - 4x - 12 = 0
\]
We solve this quadratic equation using the quadratic formula \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\), where \(a = 1\), \(b = -4\), and \(c = -12\):
\[
x = \frac{4 \pm \sqrt{16 + 48}}{2}
\]
\[
x = \frac{4 \pm \sqrt{64}}{2}
\]
\[
x = \frac{4 \pm 8}{2}
\]
This gives us two solutions:
\[
x = \frac{4 + 8}{2} = 6
\]
\[
x = \frac{4 - 8}{2} = -2
\]