Or a lightbox with normal paper, or a window with light on the other side.

Thanks for the info mathsyperson, the 90 degrees was just a guess. I knew the 2 axis were flipping somehow.]]>

I think these excersizes are meant to teach you understand how the functions work, I understand why the curve is the way it is given a particular point, but I find I can't sketch it accurately without inserting values into the equation. But if I just try to sketch it generally, then I pretty much need to ignore whats happening and just sketch the pattern, which teaches me little.

]]>Sketching tangent curves are slightly more difficult.

But when it comes to sketching the arc forms of trigonometric functions, I don't really know what to do. I could just study the patern that develops with each one, but that teaches me little. I could plot the points one by one in a few spots by just inserting values into the function, but I think this is cheating. I'm not really sure what else I'm supposed to do.

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