Questions: Find f'(x) and find the equation of the line tangent to the graph of f at x = 3, where f(x) = (4x - 3)^(1/2)
f'(x) =
The equation of the tangent line is y =
A. The tangent line is horizontal at x = 3.
B. The tangent line is never horizontal.
Transcript text: [
Quiz: Module 08: Quiz on Section 3.4:
Question list:
Question 7
Question 6
Question 5
Question 4
Question 3
Question 2
Question 1
Find f'(x) and find the equation of the line tangent to the graph of f at x = 3, where f(x) = $(4x - 3)^{1/2}$
f'(x) =
The equation of the tangent line is y =
A. The tangent line is horizontal at x = 3.
B. The tangent line is never horizontal.
Time Remaining: 00:27:42
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]
Solution
Solution Steps
Step 1: Find the Derivative
To find the derivative of the function \( f(x) = (4x - 3)^{1/2} \), we apply the chain rule. The derivative is given by:
\[
f'(x) = \frac{2}{\sqrt{4x - 3}}
\]
Step 2: Evaluate the Derivative at \( x = 3 \)
Next, we evaluate the derivative at \( x = 3 \) to find the slope of the tangent line:
\[
f'(3) = \frac{2}{\sqrt{4(3) - 3}} = \frac{2}{\sqrt{9}} = \frac{2}{3}
\]
Step 3: Find the Equation of the Tangent Line
We also need to find the value of the function at \( x = 3 \):
\[
f(3) = \sqrt{4(3) - 3} = \sqrt{9} = 3
\]
Using the point-slope form of the equation of a line, \( y - y_1 = m(x - x_1) \), where \( m = \frac{2}{3} \) and \( (x_1, y_1) = (3, 3) \), we can write the equation of the tangent line:
\[
y - 3 = \frac{2}{3}(x - 3)
\]
Simplifying this, we find:
\[
y = \frac{2}{3}x + 1
\]
Final Answer
\( f'(x) = \frac{2}{\sqrt{4x - 3}} \)
The equation of the tangent line is \( y = \frac{2}{3}x + 1 \).
The correct answer is B.