Andrew is using symbols like the big R and epsilon without ever explaining what they mean. Did he explain them in an earlier course?

Lecture: https://www.coursera.org/learn/neural-networks-deep-learning/lecture/Z8j0R/binary-classification

Timestamp: 4:40

Please update you post with a link to the lecture, timestamp and slide.

āBig Rā is a standard mathematical reference to the space of real numbers. It will also have a superscript that specifies how many dimensions are being considered.

āepsilonā is a common variable used to refer to small changes in some experimental value.

Hello Tyler,

Welcome to the community and thank you for your question.

You can find all the notations used in DLS course from the following link:

Ok, I did, thank you

Ok I guess it isnāt epsilon, itās the one that looks like a fork or like a rounded capital E. You say itās standard, for what kind of math?

Thank you Rashmi, but that does not help. That page does not define the big R symbol or the rounded E symbol.

Please post a screen capture image that shows the symbols youāre asking about. I donāt recognize ārounded Eā.

\in = is in

eg:

If x \in \mathbb{R}, x belongs to the set of real numbers.

Please see

`Basic concepts and notation`

section here- Set builder notation