It's a Herculean task trying to reeducate mainstream academics.

My historic geometric theorem:

https://drive.google.com/open?id=1RDulODvgncItTe7qNI1d8KTN5bl0aTXj

explains a general formula for any derivative using geometry.

It also proves that both differentiation and integration can be done without any limit theory or other ill-formed concepts such as infinity and infinitesimals:

https://drive.google.com/open?id=1uIBgJ1ObroIbkt0V2YFQEpPdd8l-xK6y

But it's very difficult trying to reeducate dishonest mainstream math academics. They are vile creatures who hate and oppose anyone with different ideas, no matter how good.

My LinkedIn article explains:

https://www.linkedin.com/pulse/how-stupid-mainstream-math-professors-john-gabriel/

A link to the applets used in the video:

Derivative through geometry:

https://drive.google.com/open?id=1ON1GQ7b6UNpZSEEsbG14eAFCPv8p03pv

Fraudulent Calculus:

https://drive.google.com/open?id=14Ua0EPFAUUpNXZXzIdAzXASBqr2yC_wO

Link to article about Lipschitz Condition (Page 118-120):

https://ia801905.us.archive.org/27/items/in.ernet.dli.2015.134298/2015.134298.Intermediate-Mathematical-Analysis.pdf

Link to retired math professor's (Gerry Folland) drivel:

https://sites.math.washington.edu/~folland/Math134/lin-approx.pdf

Links to my battle against the BIG STUPID (mainstream academia):

https://groups.google.com/d/msg/sci.math/MRM9uACbr80/0oZ8IqYxCAAJ

https://groups.google.com/d/msg/sci.math/tNd0WzhXYL0/8PFJOp81AQAJ