Equation of Tangent Plane with Vector-Valued Function

In summary, to find the equation of the tangent plane to a vector-valued function at the origin, you must first set the function equal to <0,0,0> and solve for the variables u and v. Then, evaluate the partial derivatives of the function at (0,0) to find the normal vector to the plane. Finally, use this normal vector to write the equation of the plane using the point (0,0,0).
  • #1
atm1993
3
0

Homework Statement


Find an equation of the tangent plane to the vector valued function at the origin, (0,0,0).

Homework Equations


The Attempt at a Solution


I don't really know how to start. I've been reading and searching around for quite a bit. I know how to do the problem with a regular function, using the partial derivatives of a function and such, but I'm not really sure where to go with this vector-valued function.
 
Last edited:
Physics news on Phys.org
  • #2
atm1993 said:

Homework Statement


Find an equation of the tangent plane to r(u,v) = uvi + ue^vj + ve^uk at the origin, (0,0,0).



Homework Equations





The Attempt at a Solution


I don't really know how to start. I've been reading and searching around for quite a bit. I know how to do the problem with a regular function, using the partial derivatives of a function and such, but I'm not really sure where to go with this vector-valued function.

The first step is to figure out what u and v give R(u,v) = <0,0,0>.

Then use the fact that Ru X Rv evaluated at that point (u,v) gives a normal vector to the plane. You can use that to write its equation.
 
  • #3
Alright, so I worked it out and I want to see if I'm on the right track following what you said.

For the function to = <0,0,0>, (u,v) would have to be (0,0). I then found the partials of the function with respect to u and v.


ru(u,v) = vi + e^vj + ve^uk
and
rv(u,v) = ui + ue^vj + e^uk

I then evaluated both of those at (0,0), resulting in

<0, 1, 0> and <0, 0, 1>.

Crossing those resulted in <1, 0, 0>, which then leaves me with an equation of a plane as x=0, using the point (0, 0, 0).

I'm not completely sure if I did that correctly.
 
  • #4
atm1993 said:
Alright, so I worked it out and I want to see if I'm on the right track following what you said.

For the function to = <0,0,0>, (u,v) would have to be (0,0). I then found the partials of the function with respect to u and v.


ru(u,v) = vi + e^vj + ve^uk
and
rv(u,v) = ui + ue^vj + e^uk

I then evaluated both of those at (0,0), resulting in

<0, 1, 0> and <0, 0, 1>.

Crossing those resulted in <1, 0, 0>, which then leaves me with an equation of a plane as x=0, using the point (0, 0, 0).

I'm not completely sure if I did that correctly.

That looks correct to me. It just says your surface is tangent to the yz (x=0) plane at the origin.
 

FAQ: Equation of Tangent Plane with Vector-Valued Function

1. What is the equation of the tangent plane for a vector-valued function at a given point?

The equation of the tangent plane for a vector-valued function is given by z - z0 = ∇f(x0, y0).(x-x0, y-y0) , where z0 is the value of the function at the given point and ∇f(x0, y0) is the gradient vector evaluated at that point.

2. How do you find the gradient vector for a vector-valued function?

The gradient vector for a vector-valued function is found by taking the partial derivatives of the function with respect to each variable and putting them together in a vector. For example, if the function is given by f(x,y) = x2 + 2y, then the gradient vector is ∇f(x,y) = (2x, 2) .

3. What information does the equation of the tangent plane provide?

The equation of the tangent plane provides information about the slope or rate of change of the function at a specific point. It also gives the local approximation of the graph of the function near that point.

4. Can the equation of the tangent plane be used to find the normal vector to the surface?

Yes, the normal vector to the surface can be found using the gradient vector from the equation of the tangent plane. The normal vector is given by n = ∇f(x0, y0) = (fx, fy, -1) , where fx and fy are the partial derivatives of the function with respect to x and y, respectively.

5. How is the equation of the tangent plane used in applications?

The equation of the tangent plane is used in applications such as optimization problems, where it helps to find the maximum or minimum value of a function. It is also used in physics and engineering to approximate the behavior of a system at a specific point. Additionally, it is used in computer graphics to create 3D models of surfaces.

Similar threads

Replies
8
Views
1K
Replies
11
Views
3K
Replies
1
Views
1K
Replies
3
Views
1K
Replies
1
Views
1K
Replies
6
Views
1K
Back
Top