The simpler quadratic formula | Lockdown math ep. 1
3Blue1Brown
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#### Published On Apr 17, 2020

Another view on the quadratic formula.
Brought to you by you: https://3b1b.co/ldm-thanks

Beautiful pictorial summary by @ThuyNganVu:

Welch Labs on imaginary numbers:

Mistakes (there will always be mistakes):
At minute 22, I write "b' / 2" instead of "-b' / 2".

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0:00 - Introduction
2:56 - "How often am I going to use this?" + ray tracing example
5:38 - Mental math tricks (factoring numbers, differences of squares)
13:36 - Properties of quadratic functions
18:40 - Deriving the variant quadratic formula
23:07 - Practice problems (ft. complex numbers!)
41:07 - Conclusion (key takeaways)
43:21 - Fun with joke poll questions
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Music by Vincent Rubinetti.
https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown

Stream the music on Spotify:
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If you want to contribute translated subtitles or to help review those that have already been made by others and need approval, you can click the gear icon in the video and go to subtitles/cc, then "add subtitles/cc". I really appreciate those who do this, as it helps make the lessons accessible to more people.

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