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What does In x mean? (C3)

My maths teacher set us homework on mymaths and for the first part, we have to rearrange the equations into the form f(x)=0.
One of the equations is In 2x = 3. I have never came across 'In' before, although I have seen it on calculators. How do you put this equation in the form f(x) = 0 and what on Earth is In and what are you supposed to do with it?
Reply 1
Avatar for B_9710
B_9710
18
ln⁡x=log⁡ex \ln x = \log_e x .
The natural logarithm.
You do not put it in f(x)=0 form.
It's by definition. If ex=a⇒x=ln⁡a e^x=a \Rightarrow x=\ln a .
(edited 7 years ago)
http://www.rapidtables.com/math/algebra/Ln.htm
Reply 3
Avatar for Rabadon
Rabadon
11
ln is log base e. So similar if it was log base 10 on the left you'd make the right log10^3 and then remove logs from both sides.

So ln2x=3
ln2x=lne^3
2x=e^3
x=1/2(e^3)
Reply 4
Avatar for davros
davros
16
Original post by jessyjellytot14
My maths teacher set us homework on mymaths and for the first part, we have to rearrange the equations into the form f(x)=0.
One of the equations is In 2x = 3. I have never came across 'In' before, although I have seen it on calculators. How do you put this equation in the form f(x) = 0 and what on Earth is In and what are you supposed to do with it?


If you just want to put it into the form f(x) = 0, then surely all you have to do is write

ln(2x) - 3 = 0

No?
It means L times by N times by 2x.

Spoiler

(edited 7 years ago)

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