unnamed asked: How would I get the log (lg) to the other side of this equation?
lg (d/10) = - 0.46
I want d/10 to be on one side, with the log and -0.46 on the other… How can I do this using my calculator?
Any help would be appreciated.
Andrea
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log mathamatics?log ? I must have been out for this whole unit?getting rid of this freakin log?Help me solve this log problem?HOW would I do this natural log problem?log / exponential question?How do i take the natural log of both sides when the equation is y= (3x+3)^(5x+1)?
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January 10th, 2008 at 2:28 am
Raise it to the tenth power. d = 10^-04.6
January 11th, 2008 at 7:38 am
First of all we need to determine what base log you are working in. Most scientific calculators work for log base 10 and log base ‘e’ only. These are normally indentified by lg and ln respectively (ln meaning the natural log).
So, let’s assume by your equation above that you are working in log base 10.
You have to remember what the logarithm actually IS. The logarithm is the number raised to a power, so your equation:
log (d/10) = -0.46
is equivellent to
d/10 = 10^(-0.46)
Do you see how it works? The log function can’t just be carried to the other side, because it represents the opposite to an exponential (not to be confused with the natural exponential, ‘e’ or ‘exp’)
On your calculator (probably as a second function on the log (lg) button) there will be a 10^x symbol. That is how you elliminate the log from the equation, it becomes:
d/10 = 10^(-0.46)
So if you need to find d:
d = 10 * 10^(-0.46) = 3.467
It is a simple as that.
PS: Stevers1 is on the right track, but his answer is wrong.
January 12th, 2008 at 4:40 pm
On a calculator use the 10^x button. On some calculators you have to do INV Log or 2nd Log etc. Basically you just need to do the opposite operation to the LOG key.
So for your problem, enter the following keys -
0
.
4
6
+/- (unary minus, sometimes shown as +/-, sometimes as (-) or just a small - sign)
10^x (or Inv LOG, or 2nd LOG depending on your calculator.)