Comments on: How do you inverse log in an equation using a scientific calculator? http://www.about-siding.com/how-do-you-inverse-log-in-an-equation-using-a-scientific-calculator/158/ Your Questions, Our Answers Mon, 21 May 2012 05:33:30 +0000 http://wordpress.org/?v=2.2.1 By: Timbo http://www.about-siding.com/how-do-you-inverse-log-in-an-equation-using-a-scientific-calculator/158/#comment-241 Timbo Sat, 12 Jan 2008 20:40:33 +0000 http://www.about-siding.com/how-do-you-inverse-log-in-an-equation-using-a-scientific-calculator/158/#comment-241 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.) 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.)

]]> By: Mawkish http://www.about-siding.com/how-do-you-inverse-log-in-an-equation-using-a-scientific-calculator/158/#comment-240 Mawkish Fri, 11 Jan 2008 11:38:56 +0000 http://www.about-siding.com/how-do-you-inverse-log-in-an-equation-using-a-scientific-calculator/158/#comment-240 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. 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.

]]> By: stevers1 http://www.about-siding.com/how-do-you-inverse-log-in-an-equation-using-a-scientific-calculator/158/#comment-239 stevers1 Thu, 10 Jan 2008 06:28:13 +0000 http://www.about-siding.com/how-do-you-inverse-log-in-an-equation-using-a-scientific-calculator/158/#comment-239 Raise it to the tenth power. d = 10^-04.6 Raise it to the tenth power. d = 10^-04.6

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