3D geometry: parametric equation and tangents

In summary, the conversation discusses a parametric equation in 3D space and its representation as a curve. The derivative of the vector function with respect to the parameter t gives the tangent vector to the curve at any given point.
  • #1
AdityaDev
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I have a doubt in 3d geometry. I calculus and I know how to do partial derivatives.(but I don't know what it means).
If you have a parametric equation ##x=t, y=t^2,z=t^3## (the equation is randomn)
What does ##\vec{r}=t\hat{i}+t^2\hat{j}+t^3\hat{k}## represent?
now if it represents the position vector or the vector connecting origin and a point on the curve, then will ##\frac{dr}{dt}## give the tangent to the curve?
 
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  • #2
AdityaDev said:
I have a doubt in 3d geometry. I calculus and I know how to do partial derivatives.(but I don't know what it means).
If you have a parametric equation ##x=t, y=t^2,z=t^3## (the equation is randomn)
What does ##\vec{r}=t\hat{i}+t^2\hat{j}+t^3\hat{k}## represent?
It represents a curve in three-dimensional space. For each value of the parameter t, you get a vector from the origin to a point on the curve. To see what this curve looks like, plot 8 or 10 points and connect them.
AdityaDev said:
now if it represents the position vector or the vector connecting origin and a point on the curve, then will ##\frac{dr}{dt}## give the tangent to the curve?
Yes
 
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FAQ: 3D geometry: parametric equation and tangents

1. What is a parametric equation in 3D geometry?

A parametric equation in 3D geometry is a mathematical expression that describes the position of a point in three-dimensional space as a function of one or more parameters. It is commonly used to represent curves and surfaces in three dimensions.

2. How are parametric equations used in 3D modeling?

In 3D modeling, parametric equations are used to create and manipulate three-dimensional objects. By defining the position, size, and shape of points, curves, and surfaces using parametric equations, complex 3D models can be easily constructed and modified.

3. What is the concept of tangents in 3D geometry?

In 3D geometry, tangents refer to the lines or planes that touch a curve or surface at a single point, without intersecting it. They represent the instantaneous direction of the curve or surface at that point.

4. How do you find the tangent to a curve using parametric equations?

To find the tangent to a curve defined by parametric equations, you can use the derivative of the equations with respect to the parameter. This will give you the slope of the tangent line, which can then be used to find the equation of the tangent line at a specific point.

5. Can parametric equations be used to calculate surface area and volume in 3D geometry?

Yes, parametric equations can be used to calculate surface area and volume in 3D geometry. By integrating the parametric equations over a given interval, you can find the surface area or volume of a curve or surface represented by the equations.

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