Questions: Use linear approximation, i.e. the tangent line, to approximate √49.3 as follows: Let f(x)=√x. Find the equation of the tangent line to f(x) at x=49
L(x)=
Using this, we find our approximation for √49.3 is
Transcript text: Use linear approximation, i.e. the tangent line, to approximate $\sqrt{49.3}$ as follows: Let $f(x)=\sqrt{x}$. Find the equation of the tangent line to $f(x)$ at $x=49$
\[
L(x)=
\]
Using this, we find our approximation for $\sqrt{49.3}$ is
Solution
Solution Steps
Step 1: Find the derivative of $f(x)$
The derivative of $f(x)$, denoted as $f'(x)$, is found to be $\frac{1}{2 \sqrt{x}}$.
Step 2: Calculate the slope of the tangent line at $x=a$
The slope of the tangent line at $x=49$ is $m = f'(49) = 1/14$.
Step 3: Determine the y-intercept $b$ of the tangent line
Using the point-slope form, the y-intercept $b$ is calculated as $b = f(49) - m \cdot 49 = 7/2$.
Step 4: Form the equation of the tangent line $L(x)$
The equation of the tangent line is $L(x) = 1/14 \cdot (x - 49) + 7 = \frac{x}{14} + \frac{7}{2}$.
Step 5: Approximate $f(a+h)$
By evaluating $L(a+h)$, the linear approximation of $f(x)$ at $x = 49 + 0.3$ is approximately $7.021$.
Final Answer:
The linear approximation of $f(49+0.3)$ is approximately $7.021$, rounded to 9 decimal places.