Questions: Consider the following function and express the relationship between a small change in x and the corresponding change in y in the form dy=f'(x) dx.
f(x)=cot 8 x
dy=
Transcript text: Consider the following function and express the relationship between a small change in x and the corresponding change in y in the form $\mathrm{dy}=\mathrm{f}^{\prime}(\mathrm{x}) \mathrm{dx}$.
\[
f(x)=\cot 8 x
\]
\[
d y=
\]
Solution
Solution Steps
Step 1: Identify the function and its derivative
The given function is:
\[
f(x) = \cot(8x)
\]
To find the relationship between a small change in \( x \) and the corresponding change in \( y \), we need to compute the derivative of \( f(x) \) with respect to \( x \).
Step 2: Compute the derivative of \( f(x) \)
The derivative of \( \cot(u) \) with respect to \( u \) is \( -\csc^2(u) \). Using the chain rule, the derivative of \( f(x) = \cot(8x) \) is:
\[
f'(x) = -\csc^2(8x) \cdot \frac{d}{dx}(8x)
\]
\[
f'(x) = -\csc^2(8x) \cdot 8
\]
\[
f'(x) = -8\csc^2(8x)
\]
Step 3: Express the relationship between \( dy \) and \( dx \)
The relationship between a small change in \( x \) and the corresponding change in \( y \) is given by:
\[
dy = f'(x) \, dx
\]
Substituting the derivative \( f'(x) \) we found:
\[
dy = -8\csc^2(8x) \, dx
\]