In single variable calculus, you only had to take a limit from the left and from the right. In multi variable calculus, you can approach from every single direction. One way to say a limit doesn't exist is then to find two different paths where along those two different paths the limit approaches different values. Then for sure the limit of the function does not exist. However, you could find 10,100,1000 paths where the limit was the same along every path and yet the limit still didn't exist because you just hadn't found the one path that was weird yet. This is problematic and motivates upgrading the very definition of the limit from what we saw in first year calculus.
****************************************************
YOUR TURN! Learning math requires more than just watching videos, so make sure you reflect, ask questions, and do lots of practice problems!
****************************************************
►Full Multivariable Calculus Playlist: • Calculus III: Multivariable Calculus ...
****************************************************
Other Course Playlists:
►CALCULUS I: • Calculus I (Limits, Derivative, Integ...
► CALCULUS II: • Calculus II (Integration Methods, Ser...
►DISCRETE MATH: • Discrete Math (Full Course: Sets, Log...
►LINEAR ALGEBRA: • Linear Algebra (Full Course)
***************************************************
► Want to learn math effectively? Check out my "Learning Math" Series:
• 5 Tips To Make Math Practice Problems...
►Want some cool math? Check out my "Cool Math" Series:
• Cool Math Series
*****************************************************
►Follow me on Twitter: / treforbazett
*****************************************************
This video was created by Dr. Trefor Bazett.
BECOME A MEMBER:
►Join: / @drtrefor
MATH BOOKS & MERCH I LOVE:
► My Amazon Affiliate Shop: https://www.amazon.com/shop/treforbazett