2*ln x=8.8

Question

2*ln x=8.8

anonymous · Answer

is this saying 2(e^8.8)?

anonymous · Answer

$$x = e^{4.4}$$

anonymous · Answer

e^4.4=x

phi · Answer

it is saying ln x = 4.4

saifoo.khan · Answer

x = e^4.4

phi · Answer

or ln (x^2) = 8.8

saifoo.khan · Answer

x = 81.45

phi · Answer

the first way is definitely the better way to go

anonymous · Answer

why it it 2 squared?  It's 2 times ln x = 8.8  
do you divide the 8.8 in the exponent by the 2 that you are supposed to multiply by>  I am throroughly confused!

phi · Answer

It is easy (for me) to get all confused. so I'm not surprised.

anonymous · Answer

not sure of the division of the exponent.  That is what is making me confused at this point.

phi · Answer

but let's concentrate on the simple interpretation
2 ln x = 8.8
divide both sides by 2 (to get ln x by itself)

phi · Answer

the base of ln is e (2.718281828...)

anonymous · Answer

DUH?  I must be having a total brain fart!  That makes sense - then after I do that I re-arrange and make it the exponent!

phi · Answer

$e^{ln x} = e^{8.8}$

phi · Answer

but e^(ln x) = x  (memorize this!)

anonymous · Answer

I hate reviews on stuff I barely understood the first time!  UGH!  THanks for your help!

anonymous · Answer

makes no difference because of laws of exponents right?

$$\n(x^2)=8.8$$
$$x^2=e^{8.8}$$
$$x=e^{8.8\times \frac{1}{2}}$$
$$x=e^{4.4}$$ alhtough that method is a bit silly

anonymous · Answer

THANKS!

phi · Answer

Good @sat, that was the next thing to tackle.

anonymous · Answer

i have posted another one on the other side