Natural logarithm with TI-30XA calculator

The TI-30XA calculates logarithms to base e and base 10. You can calculate the log of x to any base b by calculating the logarithm of x and dividing it by the logarithm of b: log(x)/log(b) or ln(x)/ln(b).

To take the log of a number, enter the number then press the LOG button, then the =. To take the log of a negative number, enter the negative number using the +/- key just to the right of the decimal point. To calculate the negative of a log, calculate the log and then negate it using +/-. To calculate the antilog (inverse logarithm), press 2nd then LOG.

Bear in mind that LOG is the common (base-10) logarithm. For the natural (base-e) logarithm, use the LN key to its right.

What you call the antilog is also known as as the power function. More specifically, the inverse of a decimal log is the function 10 to a power, (10^x) It shares the same physical key as the log function. If the calculator has a key marked [LOG] you have to press the [2nd or SHIFT] key followed by the [LOG] key to activate the anti-log.

For natural log (logarithms in base e) the antilog is the exponential function (e^x). It shares the same physical key as the [LN] function.

Using logarithms. For example, if A ^ X = 2; then X = logA(2);
This calculator only works in base-10 logarithms or natural logarithms, you should use the base conversion formula.
logA(X) = logC(X) / logC(A).
Good luck!

Use the LOG key for common logarithms, the LN key for natural logarithms. Use the SHIFT of those keys for antilogarithms.

Example: to calculate the natural log of 2, press LN 2 =

For common antilogarithm use 2nd [10^x]. For natural antilogarithm use 2nd [e^x]. Those are the shifted functions of the two logarithm keys.

These two functions operate on the expression already entered into the calculator.

Example: to calculate the natural antilogarithm of .7:
. 7 2nd [e^x] =

Yes, there is a [LOG] key to calculate decimal logarithms (logs in base 10) it is marked LOG, and another key marked [LN] to calculate the natural logarithms (logs in base e).
You enter a positive number, then press the appropriate log key (LOG or LN) and the result will be displayed.

Use the key marked LN (for natural logarithm (or Naperian logarithm)). It takes the log of the number currently in the display.

Hi,
Sorry to contradict you but there are many types of logarithms, the most important ones are

1. the common logarithms (log in base 10),
2. the natural logarithms (logarithms in base e)
3. the binary logarithms (logarithms in base 2)

On calculators, the common logarithms are labeled [LOG], and the natural logarithms are labeled [LN].

The inverse function of the natural log function is the exponential (e^(x)), and the inverse of the log in base ten function is the function ten to the power of. It is called (sometimes) the antilog

Ex:
Question What is the antilog of 3.5678?
Answer The antilog of 3.5678 is 10^(3.5678) = 3696.579068
Verification: log(3696.57908) =3.5678

Hope it helps.

Hello,
To calculate the natural log of a number use [LN] key. You enter it as
number [LN] [=] exemple 15.32 [LN] [=] gives 2.729150164
To clculate the log base 10 (common logarithm) you use the [LOG] key
15.32 [LOG][=] gives 1.185258765.

Hope it helps