# Plot a dynamic curve

Dear all,

I was watching this video in youtube posted by Mathloger .

I was interested in simulating this curve shown at 4:00 minutes duration.

I created two circles and a point on the circles. A slider.

https://www.desmos.com/calculator/kvt41rhrnq

Independently they are working fine.

I am not sure how to tie both the sliders and get the result shown in the video.

Q1. Is it possible to do this in desmos because i have not come across plotting a line in time in desmos in the examples I have seen.

Q2. Any idea what software can be used if this is out of scope of desmos.

I teach Engineering graphics in Engg college. It would be very helpful if i show how to draw the engineering curves in software. can some one suggest me how to go about it.

Regards

Kamalakar

Hi @Kamalakar_B. I’ve had a little play with your file and if you change the step size on your variable t to 1 and start with t_2 at 180 then the blue point will trace out the cardioid. I’m not sure if/how the trace can be made to show up on the coordinate plane. Will have a bit more of an exploration and get back to you if I come with something.

Sir,
That one was not working properly as expected for cardiod. I corrected it now. This is working as per the expectation. Now the question is how to plot that time.
https://www.desmos.com/calculator/pbo4sbcsik
set the step size for t at 90 and see the x values at 90 and 270 positions. earlier animation was not doing it right for the 90 and 270 positions.

Since it is drawing propelry, now the question is how to generate the line the point is tracing
Kindly help me on this in desmos or kindly suggest some other tool which does the same.
Regards
Kamalakar

Sir,
Please find the complete animation of the CARDIOD.
https://www.desmos.com/calculator/dlavul4lo8

It is working… The line is traced.
Appreciate your time for reviewing and making comments. That was an encouragement that so one is always to hear my issues.

Regards
Kamalakar

@Kamalakar_B. That looks amazing!! I was looking at how to plot (x_3,y_3) in rectangular form which completely didn’t work. Congratulations on the solve.

Sir,
Any idea what software Mathlogger has used for simulating the animations he has done at 12:00 minutes time in the video

Looking at the colors i dont think it is done in desmos.