Integration help
 

MegaSack DRAW - This year's winner is user - rgwb
We will be in touch

[Closed] Integration help

3 Posts
2 Users
0 Reactions
66 Views
Posts: 2263
Free Member
Topic starter
 

Any mathematicians on-line today? I need assistance with a question, involving integration using substitution. I can do every example I have except this one. I keep on looking back to the rules of logarithms as I think that is a way forward but I can't get it.

So, can anyone tell me the steps to the resolution of integral 3^x dx? Unusually Wolfram Alpha doesn't help. I know the answer is 1/ln3.3^x+c.

The integration tables that I am meant to be using do not deal with this example, so I need to know how to rearrange the integrand. This is what I want help with!

Thanks, in anticipation.


 
Posted : 30/12/2010 2:44 pm
Posts: 0
Free Member
 

Think of it like this

3^x

e^(xln3)

then you can integrate

1/ln3 * 3^x + c

Sorry if it doesn't make much sense, I just woke up.


 
Posted : 30/12/2010 3:27 pm
Posts: 2263
Free Member
Topic starter
 

Spot on realman, easy-as when you know how. Thanks.


 
Posted : 30/12/2010 4:22 pm
Posts: 0
Free Member
 

Can I go back to bed then..


 
Posted : 30/12/2010 4:23 pm