Prove orthogonality of these curves

In summary, to prove the orthogonality of two curves, one must demonstrate that their tangent vectors at the points of intersection are perpendicular. This is typically done by calculating the derivatives of the equations of the curves and evaluating them at the points where the curves intersect. If the dot product of the tangent vectors equals zero, the curves are orthogonal at that intersection point.
  • #1
berlinvic
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Homework Statement
Prove orthogonality of curves
Relevant Equations
Orthogonality condition for curves
I am asked to prove orthogonality of these curves, however my attempts are wrong and there's something I fundamentally misunderstand as I am unable to properly find the graphs (I have only found for a, but I doubt the validity).

Furthermore, I am familiar that to check for othogonality (based on the video ), I need to find both derivatives and make sure their multiplication is equal to -1. However, the introduction of constant a, b in my case doesn't help that at all and I am unable to check for orthogonality.

This has been bugging me for days, I would highly appreciate if someone could put me on the right path to solve this problem
 

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  • #2
:welcome:

You've posted a 26-minute videos and some equations without much context. Please be more specific about what are your functions and how orthogonality is defined in this case.

Also, the homework guidelines require that you show us your best effort before we can help.
 
  • #3
I think I posted everything that I've worked so far. The main equation for othogonality is the multiplication of derivatives of the curves equal to minus one, I mentioned it in the post as well. Additionally, I attached the photo where I show my work trying to parametrize the curves, but I'm stuck with curve y (not sure about the correctness of curve x). This is all I can think of, if you have any more inqueries I will try my best to provide more information.
 
  • #4
berlinvic said:
I think I posted everything that I've worked so far. The main equation for othogonality is the multiplication of derivatives of the curves equal to minus one, I mentioned it in the post as well. Additionally, I attached the photo where I show my work trying to parametrize the curves, but I'm stuck with curve y (not sure about the correctness of curve x). This is all I can think of, if you have any more inqueries I will try my best to provide more information.
Are the curves: ##x^3 = 3(y -1)## and ##x(3y - 29) = 3##?
 
  • #5
PeroK said:
Are the curves: ##x^3 = 3(y -1)## and ##x(3y - 29) = 3##?
No, sorry for confusion. In the picture I attached those are ##x=\frac{1}{2}(v_1^2-v_2^2), v_1=const## and ##y=v_1v_2, v_2=const##
 
  • #6
berlinvic said:
No, sorry for confusion. In the picture I attached those are ##x=\frac{1}{2}(v_1^2-v_2^2), v_1=const## and ##y=v_1v_2, v_2=const##
Aren't those surfaces? Above the ##v_1, v_2## plane?
 
  • #7
PeroK said:
Aren't those surfaces? Above the ##v_1, v_2## plane?
I don't think so based on that, v_1 and v_2 here are some constants not volumes.
 
  • #8
Thread closed.

@berlinvic, please start a new thread with a clear problem description. Not counting this post, we're up to 7 posts in this thread and the members here still don't know exactly what the question is asking. The video you posted, as already noted, is 26 minutes long. It is unreasonable for you to expect members to watch the whole video to understand what you need to do.
Also, the attachments you posted are virtually unreadable. When I attempted to expand them, the writing is black text against a very dark background, as if what you took a picture was very dimly lit. Many posts with photos of work are similarly difficult or impossible to read, and this is why we discourage including photos of the work.
 
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FAQ: Prove orthogonality of these curves

What does it mean for two curves to be orthogonal?

Two curves are orthogonal if they intersect at a point and their tangent lines at that point are perpendicular to each other. This means the dot product of their tangent vectors at the intersection point is zero.

How do you find the tangent vectors of curves at a point?

The tangent vector of a curve at a point can be found by taking the derivative of the curve's parametric equations with respect to its parameter. For example, if a curve is given by \( \mathbf{r}(t) = (x(t), y(t)) \), then the tangent vector is \( \mathbf{r}'(t) = (x'(t), y'(t)) \).

What is the mathematical condition for orthogonality of two curves?

The mathematical condition for orthogonality of two curves is that the dot product of their tangent vectors at the point of intersection is zero. If \( \mathbf{T}_1 \) and \( \mathbf{T}_2 \) are the tangent vectors of the two curves at the intersection point, then \( \mathbf{T}_1 \cdot \mathbf{T}_2 = 0 \).

How do you prove orthogonality of two curves given by their equations?

To prove orthogonality, first find the point of intersection by solving the equations of the curves simultaneously. Then, compute the tangent vectors at the intersection point by taking the derivatives of the curves with respect to their parameters. Finally, verify that the dot product of these tangent vectors is zero.

Can you provide an example of proving orthogonality of two curves?

Consider the curves \( y = x^2 \) and \( y = -x^2 \). They intersect at the origin (0,0). The tangent vector for \( y = x^2 \) at the origin is \( (1, 0) \) and for \( y = -x^2 \) is \( (1, 0) \). The dot product of these vectors is \( 1 \times 1 + 0 \times 0 = 1 \), which is not zero, so these curves are not orthogonal. However, if the curves were \( y = x^2 \) and \( y = -x \), their tangent vectors at the origin would be \( (1, 0) \) and \( (0, -1) \), respectively. The dot product is \( 1 \times 0 + 0 \times (-1) = 0 \), proving they are orthogonal.

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