poles and singularites?

whats the difference between poles and singularites?

Yeah got a math final in a couple of hrs - pretty much fucked - any help?

∫Sin[Log[x]] dx = ∫x*Sin[u] du where u = Log[x]

well, u=Log[x] which makes du=(1/x)dx

then this would require that dx = x du

Since the substitution is off by more than a constant (a variable) you can't do this integral by simle substitution. fail.