Please help with this calc3 question. Thanks in advance!

Suppose the earth is a sphere with equation x2 + y + 22 = 1. On this earth, Edmonton has coordinates (sin(7 /6) cos(0), sin(7 /6) sin(0), cos(7 /6) ) and Hamburg has coordinates (sin(7 /6) cos( 7 /3), sin(7 /6) sin(7 /3), cos(7 /6)). Is it possible to see Edmonton and Hamburg at the same time? How far off the earth must you be