This is a bonus topic for a calculus lesson on derivatives of inverse trigonometric functions. It turns out that such a derivative is part of the calculation of the angle of a rainbow. This bonus lesson is a nice mix of physics and mathematics. The graphics in this lesson are generated using Geogebra, which is available from Geogebra.org.
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http://mathwithoutborders.com
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https://www.youtube.com/watch?v=Lim7KbKT2zU
I developed this method of creating a regular pentagon with origami a few years ago, motivated by seeing a different method that turned out to be only approximate.
http://MathWithoutBorders.com
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https://www.youtube.com/watch?v=vNThO9z59iA
This is part of a series of arithmetic lessons created for my grandkids, but I'm opening them to the world. You can access an annotated index with links on my Math Without Borders website here: https://mathwithoutborders.com/the-grandpa-project
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https://www.youtube.com/watch?v=1PXXkbquMe4
This is part of a series of arithmetic lessons created for my grandkids, but I'm opening them to the world. You can access an annotated index with links on my Math Without Borders website here: https://mathwithoutborders.com/the-grandpa-project
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https://www.youtube.com/watch?v=O0iKx-EVE8M
This is part of a series of arithmetic lessons created for my grandkids, but I'm opening them to the world. You can access an annotated index with links on my Math Without Borders website here: https://mathwithoutborders.com/the-grandpa-project
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https://www.youtube.com/watch?v=h2YSDT3biP8
Sample physics lesson. The new physics course will be available sometime in the late spring or summer of 2020. For more information go to http://mathwithoutborders.com
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https://www.youtube.com/watch?v=tPSIn4-pGoo