I do not know how to use my calaulator (casio fx-991).Please help me.

Posted on Jun 17, 2008

The Casios FX-115 ES , FX-115 ES PLus, FX-991 ES, FX-991 ES Plus C can perfom numerical differentiation at a point, and numerical integration between two given limits.

Aug 12, 2013 | Casio FX991ES Scientific Calculator

Here is the link to the Casio manual download page. I can't see your model number among them, but maybe there is a typo in your question.

Apr 06, 2012 | Casio FX-115ES Scientific Calculator

You can download the manual at

http://support.casio.com/pdf/004/fx-9750GII_Soft_E.pdf

http://support.casio.com/pdf/004/fx-9750GII_Soft_E.pdf

Jun 14, 2011 | Casio FX9750GII Graphic Calculator

Hello,

There are many different functions...

You can download the entire manual after answering a few questions at www.safemanuals.com

after using the dropdown menu for this make and model.

Good Luck!

There are many different functions...

You can download the entire manual after answering a few questions at www.safemanuals.com

after using the dropdown menu for this make and model.

Good Luck!

Oct 18, 2010 | Casio FX-115ES Scientific Calculator

I don't believe I have heard of the model FX910 you refer to. I suspect there is a typographical error: Could be 991. Any way, the FX-991 comes in several "species" and I can only give you the link to the page whence you can download the relevant manual.

Look under the "Scientific Calculators" heading. For each manual, read the whole title because one single manual may do for several calculators.

Here is the link.

Look under the "Scientific Calculators" heading. For each manual, read the whole title because one single manual may do for several calculators.

Here is the link.

Aug 25, 2010 | Casio FX-115ES Scientific Calculator

Hi,

You can download the user guide in PDF format by clicking this**link.**

**FixYa.**

You can download the user guide in PDF format by clicking this

*You'll require Adobe PDF Reader installed on your computer to view the manual. If it is not already installed on your computer, download it free from: http://get.adobe.com/reader/*

Jun 20, 2010 | Casio fx-300ES Calculator

Hello,

Sorry I clicked the post a clarification request too fast.

You cannot compute it directly. You have to use the formula

log_18(number) = ln(number)/ln(18).

Here log_18 is log in base 18, ln is the natural logarithm (naeperian or log in base e).

Alternatively, you can use

log_18(number) = log(number)/log(18)

where log is log in base 10.

If you use those types of calculations a lot, it might be a good idea to get a Casio FX-115ES, or a Casio FX-991 ES. They have other nice features like fraction calculations and radicals.

Hope it helps.

Sorry I clicked the post a clarification request too fast.

You cannot compute it directly. You have to use the formula

log_18(number) = ln(number)/ln(18).

Here log_18 is log in base 18, ln is the natural logarithm (naeperian or log in base e).

Alternatively, you can use

log_18(number) = log(number)/log(18)

where log is log in base 10.

If you use those types of calculations a lot, it might be a good idea to get a Casio FX-115ES, or a Casio FX-991 ES. They have other nice features like fraction calculations and radicals.

Hope it helps.

Oct 15, 2009 | Casio FX-300MS Calculator

Hello,

It may be due to the angle unit used. You can have angles in degrees, in radians, and in grads. You should set the default angle unit to waht you problem calls for.

To set degree as default SHIFT MODE 3

To set radians as default SHIFT MODE 4

To set grads as default SHIFT MODE 5

The values of angles calculated by the inverse trigonometric functions are in the default unit that is set . This may be the source of the wrong answers that you get.

Hope it helps.

It may be due to the angle unit used. You can have angles in degrees, in radians, and in grads. You should set the default angle unit to waht you problem calls for.

To set degree as default SHIFT MODE 3

To set radians as default SHIFT MODE 4

To set grads as default SHIFT MODE 5

The values of angles calculated by the inverse trigonometric functions are in the default unit that is set . This may be the source of the wrong answers that you get.

Hope it helps.

Sep 16, 2009 | Casio FX-115ES Scientific Calculator

Hope this will help! Good luck!

Jul 10, 2009 | Calculators

There are plenty of casio 991 manuals here. Take your pick!

http://safemanuals.com/zearch_160.php

Dom't forget to leave feedback if it solves your problem. 'fixya'!

http://safemanuals.com/zearch_160.php

Dom't forget to leave feedback if it solves your problem. 'fixya'!

Apr 24, 2008 | Calculators

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