$30
1. Write down the default inner product in C3 and show that the induced norm corresponding to this default inner product is actually the 2-norm. Let
Ñ1+ ié Ñ 1 é u = 2i ,v = 3− i ,
3+ i −i
find the norm of u and the distance between u,v under the default inner product in C3.
2. Find the 1−,2−,∞− norm unit balls in R2 and sketch them. Find all the x ∈R2 that satisfies kxk1 =kxk2 =kxk∞=1.