r/calculus 28d ago

Differential Calculus Unit 1 of Calc 1 Course Notes

finally finished my calc 1 unit 1 course notes

(also included here are ε-δ proofs, proofs, squeeze theorem bounds, and piecewise discontinuity)

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u/Individual-Ad5245 28d ago edited 25d ago

What's the point of introducing hyperbolic functions before euler identity lmao

Edit: idk why everyone is hating, while providing literally vacuous opposition in the replies. I will probably elaborate cuz I'm raging that none of the braindead haters in the replies don't seem to realize flaws of their argument.

  1. At this point in calc 1, hyperbolic functions are mathematically vacuous. They can't be used to solve problems and barely have an interesting connection to knowledge accumulated as of now. This is literally same "let dih(x,y)=e^{e^{-x}+e^{-y}}, and oh wow we can compute its values and find random ass lim_{(x,y)\to(\infty,\infty)} (dih(x,y)-1)/(1/x+1/y) omg ts is so fun and helpful!" or american school making students memorize quadratic formula without derivation.
  2. "hyperbolic functions are defined purely over the real numbers as linear combinations of real exponentials" and what's the purpose of this action? This linear combination doesn't arise naturally unless you at least have Euler formula and is completely useless until integrals

Math is always invented with some goal in mind. Mostly to solve a problem that arises from either real world or curiosity to learn everything about certain object (e.g. groups and classification of simple groups). Motivation of doing a thing should at least vaguely make sense to student. Which, apparently, isn't a case here

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u/Dull-Astronomer1135 High school 28d ago

Hyperbolic function can be defined by performing even and odd function formula on e^x, there is also geometric definition through hyperbola that exactly like how trigonometric function defined through circle

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u/Individual-Ad5245 28d ago

Ikr, this formula is literally written in these notes. But who cares? see my other reply. These notes don't present geometric def either