MASSIVE TRAUMA! log or In???????? (1 Viewer)

[enigma_1]

How do you know if you're supposed to use log or In?? I just realised that I actually don't know..

So for integration eg [integral sign] x/x+3 what do you use here?

And omg someone please help!!! I feel so confused.. Why are there 2? Log and In? When are they each used?? Helppp

 

[Squar3root]

when integrating always use ln or log base e (same thing)

 

[Squar3root]

and your other question integrate x/x+3

this will equal the expression 1 -3/(x+3) and when integrated will be x - 3ln(x+3) +c

(you can check by diffing)

 

[braintic]

For starters, it is LN, not IN (but don't write it in uppercase like that).

Further, "log_e", "ln" and "log" ALL mean log base e (despite the fact that log on the calculator means log base 10).

 

[enigma_1]

whoa omg ok thanks guys!! So to use ln when integrating, when else is it required???

 

[Squar3root]

whoa omg ok thanks guys!! So to use ln when integrating, when else is it required???

solving logaramitic equations (this depends though)

 

[enigma_1]

But isn't there like a definite way of knowing?

 

[Sy123]

 

[Squar3root]

But isn't there like a definite way of knowing?

What exactly do you mean?

 

[braintic]

Are you are worried about how a log just pops up when there is no log in the question?

Firstly in solving exponential equations.

Secondly in integrating certain rational functions (the simplest ones where the numerator and denominator are polynomials, with the denominator having a degree one higher than the numerator). But needless to say, there is more to it, and it is not as simple as that.