Questions: Find the derivative of the given function.
f(x)=(7-8 x)/(1+2 x)
f'(x)=-(22)/(1+2 x)^2
Write all x-values (if any) at which the tangent line to the graph would be horizontal.
x=
Transcript text: Find the derivative of the given function.
\[
\begin{array}{r}
f(x)=\frac{7-8 x}{1+2 x} \\
f^{\prime}(x)=-\frac{22}{(1+2 x)^{2}}
\end{array}
\]
Write all $x$-values (if any) at which the tangent line to the graph would be horizontal.
\[
x=
\]
Solution
Solution Steps
To find the x-values where the tangent line to the graph is horizontal, we need to determine where the derivative of the function is equal to zero. A horizontal tangent line occurs when the slope of the tangent (the derivative) is zero. Therefore, we set the derivative \( f'(x) \) equal to zero and solve for \( x \).
Step 1: Identify the Condition for Horizontal Tangent
To find the x-values where the tangent line to the graph is horizontal, we need to set the derivative of the function equal to zero. A horizontal tangent occurs when the slope of the tangent line, given by the derivative \( f'(x) \), is zero.
Step 2: Analyze the Derivative
The derivative of the function is given by:
\[
f'(x) = -\frac{22}{(1 + 2x)^2}
\]
We set this equal to zero to find the x-values where the tangent is horizontal:
\[
-\frac{22}{(1 + 2x)^2} = 0
\]
Step 3: Solve the Equation
The equation \(-\frac{22}{(1 + 2x)^2} = 0\) has no solutions because a fraction is zero only when its numerator is zero. Since the numerator \(-22\) is a constant and not zero, the equation has no solutions.