Mathworld FYI

[JacksinPA]

Another online math teaching resource. I found this one by searching for spherical trigonpmetry which Khan apparently doesn't include.

Wolfram MathWorld: The Web's Most Extensive Mathematics Resource

Comprehensive encyclopedia of mathematics with 13,000 detailed entries. Continually updated, extensively illustrated, and with interactive examples.

mathworld.wolfram.com

 

[dmpi]

I've done a bunch of work in navigation so I actually know a thing or two about spherical geometry. Note that people complain about the flat earth types as ignorant yet very few know how work with anything other than plane geometry.

 

[EdwinWillers]

Another online math teaching resource. I found this one by searching for spherical trigonpmetry which Khan apparently doesn't include.

Wolfram MathWorld: The Web's Most Extensive Mathematics Resource

Comprehensive encyclopedia of mathematics with 13,000 detailed entries. Continually updated, extensively illustrated, and with interactive examples.

mathworld.wolfram.com

I'll have to check that out. I've really enjoyed Khan.

 

[JacksinPA]

Another online math teaching resource. I found this one by searching for spherical trigonpmetry which Khan apparently doesn't include.

Wolfram MathWorld: The Web's Most Extensive Mathematics Resource

Comprehensive encyclopedia of mathematics with 13,000 detailed entries. Continually updated, extensively illustrated, and with interactive examples.

mathworld.wolfram.com

I checked both MathWorld & Khan Academy to evaluate their teaching techniques. In the case of MW, I chose the geometry of something simple: the circle. No instructor's voice to explain each element as I found with KA explaining vectors. MW was only text & it got into the weeds quickly with complex calculus formulas & examples from Archimedes PDQ. Check it out for yourself but KA I found to be student-friendly but MW not. MW is valuable as a reference but not as a math teaching aid IMO.

Another online math teaching resource. I found this one by searching for spherical trigonpmetry which Khan apparently doesn't include.

Wolfram MathWorld: The Web's Most Extensive Mathematics Resource

Comprehensive encyclopedia of mathematics with 13,000 detailed entries. Continually updated, extensively illustrated, and with interactive examples.

mathworld.wolfram.com

This is typical of the kind of stuff you find on MW:

Bolzano's Theorem​

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If a continuous function defined on an interval is sometimes positive and sometimes negative, it must be 0 at some point.
Bolzano (1817) proved the theorem (which effectively also proves the general case of intermediate value theorem) using techniques which were considered especially rigorous for his time, but which are regarded as nonrigorous in modern times (Grabiner 1983).

Interesting stuff but do you need this to learn basic algebra, trig & calc?