Question about Texas Instruments TI-30XA Calculator

# Using the correct key combination to determine inverse log

I believe "ln" means "inverse log" and wondered how to calculate that with the TI-30XA, for example: ln(0.24)

Posted by on

• Level 3:

An expert who has achieved level 3 by getting 1000 points

Superstar:

An expert that got 20 achievements.

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

• Texas Instru... Master

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

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.

Posted on Nov 29, 2009

SOURCE:

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

×

my-video-file.mp4

×

## Related Questions:

### How to fix error mesage on TI-30Xa. Every time I press LOG an error sign comes up. how do i fix this?

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.

Nov 07, 2011 | Texas Instruments TI-30XA Calculator

### Hi, how do i calculate log^-1(-2) on my ti-30xa? thank u.

The inverse of the log function is the power function.
For log in base 10 that inverse is 10 to a power of
More generally, let b be the base of the logarithm. If y=log_b (x) then x=b^y
For your case log=log_10, to calculate the inverse you perform 10^(-2)=0.01=1/100
On calculators the log in base 10 and its inverse share the same physical key. One is accessed directly, the other is the shifted key function.

Sep 09, 2011 | Texas Instruments TI-30XA Calculator

### Hi, how do i calculate log^-1 on my ti-30xa? for example, in order to calculate log^-1(-2), what do i do? thank you.

The inverse of the common log function is the power function with base 10 (10^). It shares the same physical key as the log. You acees the function by pressing [2nd] [log]

Sep 09, 2011 | Texas Instruments TI-30XA Calculator

### How do you find the log of 9.01 using TI 30xA calculator?

To calculate the common (base 10) log of 9.01, press 9 . 0 1 LOG =
To calculate the natural (base 3) log of 9.01, press 9 . 0 1 LN =

Both the LOG and LN keys are on the top row of the keyboard.

May 09, 2011 | Texas Instruments TI-30XA Calculator

### How do I work the anti log on TI-30X 2s? Where are the buttons?

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.

May 09, 2011 | Texas Instruments TI-30XA Calculator

### What button do you push on the TI-86 calculator to do the inv log function?

For the inverse natural log, press 2nd LN. For the inverse common log, press 2nd LOG.

For example, to calculate the inverse natural log of 2, press 2nd LN 2 ENTER and you'll get about 7.389 .

Jan 25, 2011 | Texas Instruments TI-86 Calculator

### How do I key in log and inverse log at the same time?

There are very few instances where you have two press two keys AT THE SAME TIME, the most notable of them is when you want to force the calculator into the BOOT SCREEN. Most key combinations are key sequences, meaning you press a key and THEN press another.

This said, let us get back to your question.

When you apply a function on an expression, then apply the inverse of the function on the result you get the original expression back.
If f is a function and f^-1 its inverse, by definition f^-1[f(x)]=f[f^-1(x)] =x
As you can see you do not need a calculator to find the result.

Concerning the logarithmic functions

For the natural logarithms (logarithms in base e) labeled [ln], the inverse of the logarithm is the exponential function e^
ln[e^(x)] =e^[ln(x)] =x

For the common logarithms (logarithms in base 10), labeled [log], the inverse function of the log is the raising 10 to the power of. It is usually called the antilogarithm or antilog.

y= log(x) is equivalent to x=10^(y)

Try the following exemple

log(14) = 1.146128036
10^(1.146128036) =14

To access the 10^x function you press [2nd][LOG]
To access the exponential function you press [2nd][LN]

Jan 06, 2010 | Texas Instruments TI-84 Plus Calculator

### Ln inverse function

i want to get 250 tan 35 i dont know how?can u tell me plz

Apr 14, 2009 | Texas Instruments TI-30XA Calculator

### CAn't find the inverse log on the calculator

Press "2nd LN" which gives you the exponential (inverse natural log) of 7.41 = 1652.426....

Pressing LN will give you back 7.41

Same procedure to use logs to base 10, use LOG and 2nd LOG

Dec 07, 2008 | Texas Instruments TI-30XA Calculator

### TI-30XA

Use the inverse log key sequences "2nd LN" or "2nd LOG" depending on whether you are using natural logs or logs to base 10

Dec 10, 2007 | Texas Instruments TI-30XA Calculator

## Open Questions:

#### Related Topics:

1,176 people viewed this question

Level 3 Expert

Level 3 Expert