The Historic Geometric Theorem which solves both the tangent line problem and the area problem in calculus.

Description
The Historic Theorem:

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

How it fixes the bogus mainstream formulation of calculus:

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

This knowledge has never been realised before. It is the first time in human history that this theorem is revealed.

The new definitions are a result of the well-formed concepts in
my New Calculus, the first and only rigorous formulation of
calculus in human history. What you are about to read is
historic! It has NEVER been realized before. It has NEVER been
published anywhere in any form whatsoever and it is almost
certain that no other human even came close to realising this
knowledge. There is ONE differentiation formula for all
functions and the implications are many, but here are just a
few:
1. No need to learn limit theory or real analysis and solid
proof that the mainstream formulation of calculus is a
kludge based on ill-formed concepts. This knowledge
reveals without any doubt that limit theory is neither
required in calculus, nor is it rigorous. The mainstream
calculus was never rigorous.
2. A rigorous and complete geometric derivation that refutes
Cauchy’s ideas about not being able to define the
derivative by any means other than algebra.
3. Easy to learn using only high school geometry and
trigonometry.
4. No need to learn many differentiation rules and
techniques. The ONE formula works on any function.
This ingenious idea came to me through my research on how to
produce a complete rigorous geometric formulation. The
inspiration is to produce a perpendicular from one endpoint of
the non-parallel secant line and form similar triangles, thus
reducing the problem to one of trigonometry (a specialized
geometry of triangles).