Can a disk be a square ?
22:06
Convergence in Rn
33:36
Completion of a metric space
8:11
Can a ball be a sphere?
27:26
This open problem taught me what topology is
12:55
A Strange Map Projection (Euler Spiral) - Numberphile
49:49
Way beyond the golden ratio: The power of AB=A+B (Mathologer masterclass)
32:33
What is a closed set ?
15:13