# Friday math movie - free math videos by Khan Academy

By Murray Bourne, 16 Jul 2010

I know these have been around a while, but I haven't featured it before.

Khan Academy is headed by Salman Khan who quit his day job to produce free math videos on YouTube. The videos are popular, and worth checking out.

His style is relaxed and non-threatening.

I just wish he would use black text on white background - it would be easier to watch than the current white on black.

Here's one of his more popular videos: Unit Circle Definition of Trig Functions.

See the 1 Comment below.

### One Comment on “Friday math movie - free math videos by Khan Academy”

1. Someone says:

Actually I think black background is better than white, as the black background could let me watch for hours without making my eyes too tired.

### Comment Preview

HTML: You can use simple tags like <b>, <a href="...">, etc.

To enter math, you can can either:

1. Use simple calculator-like input in the following format (surround your math in backticks, or qq on tablet or phone):
a^2 = sqrt(b^2 + c^2)
(See more on ASCIIMath syntax); or
2. Use simple LaTeX in the following format. Surround your math with $$ and $$.
$$\int g dx = \sqrt{\frac{a}{b}}$$
(This is standard simple LaTeX.)

NOTE: You can mix both types of math entry in your comment.

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