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Find the curvature at the generic point p.

User Zadops
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2 Answers

6 votes

Final Answer:

To find the curvature at a generic point ( P ), you can use the formula
\( \kappa = \frac{\left\lvert \mathbf{T}'(t) \right\rvert}{\left\lvert \mathbf{r}'(t) \right\rvert} \), where \( \mathbf{T}(t) \) is the unit tangent vector and
\( \mathbf{r}(t) \) is the position vector of the curve.

Step-by-step explanation:

Curvature measures how much a curve deviates from being a straight line at a given point. In the formula
\( \kappa = \frac{\left\lvert \mathbf{T}'(t) \right\rvert}{\left\lvert \mathbf{r}'(t) \right\rvert} \), \( \mathbf{T}'(t) \) is the derivative of the unit tangent vector
\( \mathbf{T}(t) \) with respect to the parameter ( t ), and
\( \mathbf{r}'(t) \) is the derivative of the position vector
\( \mathbf{r}(t) \) with respect to ( t ).

The unit tangent vector
\( \mathbf{T}(t) \) is defined as
\( \mathbf{T}(t) = \frac{\mathbf{r}'(t)}{\left\lvert \mathbf{r}'(t) \right\rvert} \). Taking the derivative of
\( \mathbf{T}(t) \) gives \( \mathbf{T}'(t) = \frac{\mathbf{r}''(t) \left\lvert \mathbf{r}'(t) \right\rvert - \mathbf{r}'(t)\mathbf{r}'(t)'}{\left\lvert \mathbf{r}'(t) \right\rvert^2} \).

Substituting these expressions into the curvature formula, we get
\( \kappa = \frac{\left\lvert \mathbf{r}''(t) \right\rvert}{\left\lvert \mathbf{r}'(t) \right\rvert} \). This gives the curvature at a generic point ( P ) on the curve described by the position vector
\( \mathbf{r}(t) \).

User Christian Lescuyer
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0 votes

Final Answer:

The curvature at the generic point P is given by the formula K = |T'(t)| / |r'(t)|, where T(t) is the unit tangent vector and r(t) is the position vector.

Step-by-step explanation:

Curvature measures how fast a curve is turning at a given point. In the formula K = |T'(t)| / |r'(t)|, T(t) is the unit tangent vector, which indicates the direction of the curve, and r(t) is the position vector that traces the curve. The prime notation denotes the derivative with respect to the parameter t.

The numerator, |T'(t)|, represents the rate of change of the unit tangent vector. If the curve is turning rapidly, the magnitude of T'(t) will be larger, indicating higher curvature. The denominator, |r'(t)|, represents the speed of the curve's traversal. A faster-moving curve, as indicated by a larger |r'(t)|, contributes to a lower curvature value.

Essentially, the curvature at a point P is the ratio of how quickly the curve is turning to how quickly it is traversing space. If the curve is turning sharply relative to its speed, the curvature will be high, signifying a more pronounced curve. Understanding curvature is crucial in various fields such as physics, computer graphics, and robotics, where precise control and prediction of paths are essential.

User Jay Lamont
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7.9k points