you can write “vector” CB = e^(ipi/3)CA since it’s equilateral
i’m just going to use zA=a, zB=b, zC=c
i.e.
b-c=(a-c) e^(ipi/3)
so b=c(1-e^(ipi/3))+ae^(ipi/3)
we know that:
b=xb+5i
c=xc-5i
subbing c and a into above the expression for b, you get an expression for b in terms of xc, and you...