7 Find arc length: r(t) = 3 cos ti + 3 sin tj + 5t²k Find K: r(t) =< 6, e-7t, 9te-5t >; t = 0

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Chapter2: Second-order Linear Odes
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Please help find the arc length of the function provided in the photo below as well as finding K in the second problem
### Calculus Problem: Arc Length and Curvature

#### Problem 1: Find Arc Length
Given the vector function:
\[ \mathbf{r}(t) = 3 \cos(t) \mathbf{i} + 3 \sin(t) \mathbf{j} + 5t^{\frac{7}{2}} \mathbf{k} \]

#### Problem 2: Find Curvature \(\mathbf{K}\)
Given the vector function:
\[ \mathbf{r}(t) = \langle 6, e^{-7t}, 9te^{-5t} \rangle; \ \ t = 0 \]

### Explanation:

1. **Finding Arc Length:**
   To find the arc length \( L \) of a parametrized curve represented by \( \mathbf{r}(t) \) over an interval \([a, b]\), we use the formula:
   \[
   L = \int_a^b \| \mathbf{r}'(t) \| \, dt
   \]
   where \( \mathbf{r}'(t) \) is the derivative of \( \mathbf{r}(t) \) with respect to \( t \), and \( \| \mathbf{r}'(t) \| \) is the magnitude of \( \mathbf{r}'(t) \).

2. **Finding Curvature \( K \):**
   The curvature \( K \) of a vector function \( \mathbf{r}(t) \) at a point \( t = t_0 \) can be found using the formula:
   \[
   K = \frac{\| \mathbf{r}'(t) \times \mathbf{r}''(t) \|}{\| \mathbf{r}'(t) \|^3}
   \]
   Here, \( \mathbf{r}'(t) \) is the first derivative, \( \mathbf{r}''(t) \) is the second derivative, and \( \times \) denotes the cross product. The magnitude \( \| \mathbf{r}'(t) \times \mathbf{r}''(t) \| \) gives the numerator, and the denominator is the cube of the magnitude of the first derivative. You need to evaluate this formula at \( t = 0 \).

These steps outline the fundamental process for determining the arc length and
Transcribed Image Text:### Calculus Problem: Arc Length and Curvature #### Problem 1: Find Arc Length Given the vector function: \[ \mathbf{r}(t) = 3 \cos(t) \mathbf{i} + 3 \sin(t) \mathbf{j} + 5t^{\frac{7}{2}} \mathbf{k} \] #### Problem 2: Find Curvature \(\mathbf{K}\) Given the vector function: \[ \mathbf{r}(t) = \langle 6, e^{-7t}, 9te^{-5t} \rangle; \ \ t = 0 \] ### Explanation: 1. **Finding Arc Length:** To find the arc length \( L \) of a parametrized curve represented by \( \mathbf{r}(t) \) over an interval \([a, b]\), we use the formula: \[ L = \int_a^b \| \mathbf{r}'(t) \| \, dt \] where \( \mathbf{r}'(t) \) is the derivative of \( \mathbf{r}(t) \) with respect to \( t \), and \( \| \mathbf{r}'(t) \| \) is the magnitude of \( \mathbf{r}'(t) \). 2. **Finding Curvature \( K \):** The curvature \( K \) of a vector function \( \mathbf{r}(t) \) at a point \( t = t_0 \) can be found using the formula: \[ K = \frac{\| \mathbf{r}'(t) \times \mathbf{r}''(t) \|}{\| \mathbf{r}'(t) \|^3} \] Here, \( \mathbf{r}'(t) \) is the first derivative, \( \mathbf{r}''(t) \) is the second derivative, and \( \times \) denotes the cross product. The magnitude \( \| \mathbf{r}'(t) \times \mathbf{r}''(t) \| \) gives the numerator, and the denominator is the cube of the magnitude of the first derivative. You need to evaluate this formula at \( t = 0 \). These steps outline the fundamental process for determining the arc length and
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