question (1 Viewer)

[auzbabe4christ]

oh ok.. i didnt know u could say the limit doesnt exist.. thanx..

um, maths187 im just havin totally mind blanks about wot im sposed to be doing cuz i havent done it for like 5month. so thanx

 

[auzbabe4christ]

can somebody help me with this question please..

d/dx ln(x/(x^2-4))

ive tried it so many times but it isnt working for me... any help would b appreciated!!

 

[acullen]

d/dx ln(x/(x² - 4))

Recall the log law that log(a/b) = log(a) - log(b)

d/dx ( ln(x) - ln(x² - 4 ) )

d/dx of ln(f[x]) = f'[x]/f[x]

= 1/x - 2x/(x² - 4)

 

[auzbabe4christ]

yea, well i got that.. but cant it be simplified anymore?? or is that it??

ts just it seems to simple to finsih there. thats all.

 

[acullen]

You could take it a little further, but it shouldn't be necessary...

= 1/x - 2x/(x² - 4)
= 1(x² - 4)/x(x² - 4) - 2x(x)/(x² - 4)x
= (x² - 4)/(x³-4x) - 2x²/(x³-4x)
= (x² -2x² - 4)/(x³-4x)
= (-x² - 4)/(x³-4x)

 

[auzbabe4christ]

alright. sweet. thanx.

i also have a question where i have never seen these symbols before... could u help me with this?

the question is..

Evaluate g(t^2-1) for t € R (altho that "e" thing only has one line in the middle.. i couldnt find another thing close to it)

 

[Sober]

alright. sweet. thanx.

i also have a question where i have never seen these symbols before... could u help me with this?

the question is..

Evaluate g(t^2-1) for t € R (altho that "e" thing only has one line in the middle.. i couldnt find another thing close to it)

∈ is a symbol meaning "is a member of" and the capital R (usually written with a double stroke) means "the real numbers". This notation is set theory.

 

[auzbabe4christ]

∈ is a symbol meaning "is a member of" and the capital R (usually written with a double stroke) means "the real numbers". This notation is set theory.

ok, an so if that is so. how do i do the question?? i dont remember anything like this wen i did 3-unit...

 

[Riviet]

Trev, just underline the plus to get a "plus or minus" sign in one.

ie u=x+√(x²+1)

N.B I didn't realise this thread was 4 pages until just now. XD
This post was referring to the posts on the first page.

 

[auzbabe4christ]

lol thats alright man. thanx anywayz.