If there's a math topic you're struggling with, take a look at the resources below. They are grouped by topic, and there's a good chance you can find something that will help! I welcome your feedback about any of these materials, as well as suggestions for new materials to link to (or create). The links shown in red are of my own making. I also want to thank the University of Colorado's math department, whose active calculus page supplied a number of these links.
"Arithmetic is to math as spelling is to journalism" - Emmanuel Schanzer
Here is a 3-part video of me introducing antiderivatives:
While all 6 trig functions are defined as ratios between 2 sides of a right triangle, you can find all 6 as single distances in these diagrams. Try the black and white diagram first, then the color diagram (where each color is one trig function). Here is a video with the solution.
Integrals are all about dividing a region up into small pieces. This is especially tricky to visualize with triple integrals, but I have made some videos I think will help. In each one, I slice up a potato according to how a 3D region should be sliced to calculate a triple integral. My videos include standard rectangular coordintes (dz dy dz), cylindrical coordinates (dz dr dθ), and spherical coordinates (dρ dφ dθ).