## 9768 #30 #56 #60 #63

Forum for the GRE subject test in mathematics.
breezeintopl
Posts: 16
Joined: Sun Jul 19, 2009 12:29 pm

### 9768 #30 #56 #60 #63

#30
I want to ask C and D.
#56
how to show that $\sqrt{d}$ is also a metric?
#60
I can just work out II, and only get ...maybe...s(st-ts)t=0...
why I and III are all right?
#63
why these two curve intersect 2 points when x>0?why not 0 or 1?

Thank you very much!