Questions: Find f(a), f(a+h), and the difference quotient (f(a+h)-f(a))/h, where h ≠ 0.
f(x)=4/(x+2)
f(a)=
f(a+h)=
(f(a+h)-f(a))/h=
Transcript text: Find $f(a), f(a+h)$, and the difference quotient $\frac{f(a+h)-f(a)}{h}$, where $h \neq 0$.
\[
\begin{array}{l}
f(x)=\frac{4}{x+2} \\
f(a)=
\end{array}
\]
$\square$
\[
f(a+h)=
\]
$\square$
\[
\frac{f(a+h)-f(a)}{h}=
\]
$\square$
Solution
Solution Steps
To solve this problem, we need to evaluate the function \( f(x) = \frac{4}{x+2} \) at \( x = a \) and \( x = a + h \). Then, we will compute the difference quotient \(\frac{f(a+h) - f(a)}{h}\).
Evaluate \( f(a) \) by substituting \( a \) into the function.
Evaluate \( f(a+h) \) by substituting \( a+h \) into the function.
Compute the difference quotient \(\frac{f(a+h) - f(a)}{h}\).
Step 1: Evaluate \( f(a) \)
Given \( f(x) = \frac{4}{x+2} \), we substitute \( a = 3 \):
\[
f(a) = \frac{4}{3+2} = \frac{4}{5} = 0.8
\]
Step 2: Evaluate \( f(a+h) \)
Next, we substitute \( a = 3 \) and \( h = 0.1 \) into the function:
\[
f(a+h) = f(3+0.1) = f(3.1) = \frac{4}{3.1+2} = \frac{4}{5.1} \approx 0.7843
\]
Step 3: Compute the Difference Quotient
The difference quotient is given by:
\[
\frac{f(a+h) - f(a)}{h} = \frac{0.7843 - 0.8}{0.1} = \frac{-0.0157}{0.1} = -0.1569
\]