/biz/ - Business & Finance

>>15466207

0:15 - 0:26 : Multivariate gradient descent videos. "Partial derivatives" are confusing me. Time capping partial deriv to 30 mins.
0:26 - 0:40: Figuring out partial derivatives. Got the concept, not so much the math. Probably good enough for sake of focusing.*
0:40 - 1:15: Phone call. 35 minutes. Waste of life.
1:15 - 1:52: Feature scaling, normal equation, etc.

Leaving to walk cause this is getting overwhelming. In short, what seemed like hard work to me ended up being:

>two hours of time at desk
>less than 1.5 hrs of actual study

Whew lad, not gonna make it at this rate.

* Looks like the idea is just to see which direction the output will move if ONLY one variable is changed. So you take a derivative without regard for other variables.

> This swirly-d symbol, \partial ∂, called "del", is used to distinguish partial derivatives from ordinary single-variable derivatives

>The reason for a new type of derivative is that when the input of a function is made up of multiple variables, we want to see how the function changes as we let just one of those variables change while holding all the others constant.

https://www.khanacademy.org/math/multivariable-calculus/multivariable-derivatives/partial-derivative-and-gradient-articles/a/introduction-to-partial-derivatives