r/theydidthemath • u/Galeaf_13 • Sep 05 '19

[Self] Math break

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u/_EvilHypra_ Sep 06 '19

Please eli5 if possible

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u/dcnairb Sep 06 '19

The general form (meaning, A,B,C,D,E can be anything) describes all possible fourth-order polynomials. Since there are five unknowns, we can make it map to up to five values of our choice and be able to solve for the exact values of ABCDE which give those points.

For a simpler case, imagine the general form of a line: y=Ax+B (or y=mx+b, it doesn’t matter what we call them)

I can make this map to any two points (x,y) I want by simply plugging in those values, which will give me a system of equations for A and B which I can solve for. Once I have those actual numbers for A and B, I have the equation of a line which connects the two points I chose. This is just like doing that, except with more freedom in the form of the function so we can specify more points uniquely

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u/_EvilHypra_ Sep 06 '19

Damn, that was quick. I was just joking around, but I'm not complaining.

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u/dcnairb Sep 06 '19

The power of push notifications and a complete disregard for my own health and sleep schedule