Hi there,
To get started with the first few, you'll just need to recall a few basic identities - knowing ax =eln a x, the product rule and the quotient rule should get you through those three.
Once you've done that, think about the rules you've used and the question with s(t) should look easy.
The next one is a little messy so I'd suggest that first you try to work out da/dx for a=a2+ln(x).
For the graphing problem, think about range, value at x=0 and limits for both ends of x.
For the last bit on that page - just work through it real slow, so long as you remember the basic properties of logarithms then you should be fine.
Good luck tho!