Categories
Calculus Line Integrals Math Multivariable Calculus Vector Calculus

Find Potential Function Using Partial Integration

Once you’ve established that curl F = 0, you know that F is the gradient of some potential ⱷ. You can use the Fundamental Theorem to evaluate ∫F.dr — if only you could find the potential function. In this video I go over a straighforward method of finding the potential function using partial integration. (Note: the sound quality gets wonky near the end but you can still hear what I’m explaining perfectly well. Apologies and I’ll figure out eventually why that happens.)

Categories
Geometry Math Trigonometry

Area of Octagon Given Side Length

A step-by-step example of how to find the area of a polygon

Categories
Geometry Math Trigonometry

Area of Regular Polygon-General Strategy

Finding the area of a polygon seems impossible given just the side length or just the length of a radius or apothegm. But here’s how to do it, step by step.

Categories
Complex Numbers Math Math Analysis Pre-Calculus Trigonometry

Sin x from Euler’s Formula

Here’s one of the things about complex numbers which is easier if you know it so well you don’t have to think about it: the formula for sin x. Nice and easy. Assumes you already know Euler’s formula, eix = cos x + i sin x.

Categories
Calculus Limits Math

Precise Definition of a Limit

A clear explanation of the epsilon-delta definition of a limit

Categories
Math Analysis Pre-Calculus Proofs Proving Identities Trigonometry

Proving Trig Identities: Some Strategies

Assuming you know the basics (tan=sin/cos, etc), here are strategies and examples for proving simple trig identities.

Categories
Algebra 1 Math

Fraction Exponents

What are fraction exponents? Why is x=∛x? Here’s an explanation.

Categories
Algebra 1 Math

The Zero Power

You probably already know that 20=1. In fact any number to the power of 0 is one. But why?

Categories
Math Math Analysis Pre-Calculus Proofs

Ten-year-old Finds Math Secret! (Summing an Arithmetic Series)

Gauss was just ten years old when he discovered how to quickly add up a long series of numbers. Here I tell the story of how he outwitted his teacher and I also walk you through a mathematical proof.

Categories
Algebra 1 Math Word Problems

Algebra 1 Word Problems Involving Motion

A lively presentation of how to solve a two different word problems involving motion, using distance = rate * time. The text is a little small so click the “full screen” option to really see it. (I’ll redo this eventually — still learning ins and outs of Zoom!)