Any online math tutorial homepage I can check out?

[UncleWai]

I haven't taken a math class since highschool, right now I am taking Calc III.
I pretty much forgot every single thing about trigonometry (am i even spelling it right?)
What I need is a list of formulas on how to breakdown trig and log function.

ex. Like ln (n+1), is there anyway i can separate n and 1?

 

[Shooters]

Don't think so. I believe the only easy simplification properties for ln (and log for that matter) are

ln(a*b) = ln(a)+ln(b)

and

ln(a/b) = ln(a)-ln(b)

Oh, and another one is

ln(a^b) = b*ln(a)

Check out this website. It may not have exactly what you're looking for, but I've found it an invaluable reference for when I need to quickly look something up that I've learned before but am a little rusty on.

mathworld.wolfram.com

 

[UncleWai]

Thanks, that helped!
It's been two years since I touched a math book.

it was ln(n+1) - ln(n)
so ln((n+1)/n)
as n approaches infinity, (n+1)/n = 1, converges to ln1, win~~~~


If any kind soul want to help me out

arctan(2n)
does it converge or diverge?
how do i go about solving this one?

 

[Shooters]

seems like the answer would be pi/2 + m*pi where m is any integer