How do I get to the "i" for an irrational number on the button ENG

The best known irrational number is Pi, so, any formula with that in it it, like the formula for

circumference of a circle - Pi * D
area of a circle - Pi * R^2
volume of a sphere - 4/3 * Pi * R^3

Here D and R should be rational numbers, eg integers, to meet your definition.

It's a rational number since it can be represented as a ratio of two whole number, in this case 233 and 100.

False. A number is either rational or irrational; it cannot be both.

Sorry, you can't. The TI-84 has a limited ability to work with fractions but it won't work with irrational numbers.

Unfortunately, you can't. The TI-84 has a limited ability to work with fractions but it won't work with irrational numbers.

There are a lot of irrational numbers. In fact there're an infinite number of them. One is called "pi". Another is called "e". Another is the square root of two. Do you have a particular one in mind?

You're looking for a website with examples of rational and irrational numbers? Here's an extensive one:

1. Rational: Link
2. Irrational: Link

Or are you just asking for a few examples?

1. Rational: 5, 2/4, -34
   
2. Irrational: ?2, ?

Hope this helps!

Not all decimal representations have equivalent fractions. Take pi. Its approximate value as given by the Casio FX9750II is 3.141592654. This is just an approximation because the string of decimal digits in pi has no end. It continues . Such a number that cannot be represented by a ratio of two integers is not rational, not a fraction. It is called irrational.Other such numbers are ?2, ?3,?5, e the base of natural logarithms.
As a matter of principle, if a number is called irrational, it is because it is not rational (not a fraction), and it makes no sense to try to cast it into fraction form.

However, if you truncate an irrational number so as to keep only a finite number of decimal digits, then that truncated number can be represented by a fraction, but qualitatively speaking, it is not the original irrational number.
Thus if you decide to use 3.141500000000000000....0 as an approximate value of pi then you write
3.1415=31415/10000 and the calculator will convert it to the mixed fraction 3u283u2000. To effect this conversion, you press the [FD] key to the right of [a b/c]. If you want an improper fraction 6283u2000 you press [SHIFT][[FD].

As to the value of sin 45 you quote, you should be aware that it is valid for an angle unit in radians.
It is an approximation because the radian unit is based on the value of pi, which, as I said above, is an irrational number.
If you use the degree angle unit, sin45 deg is actually equal to 1/?2 or ?2/2 and this is clearly irrational, and it cannot be represented as a fraction. In conclusion it makes no sense to try to cast it into such form.
On the other hand, sin 30 deg or cos 60 deg are both exactly equal to 1/2. The calculator will convert them to a fraction.

On a more general note, the calculator will always be able to convert a fraction into an approximate decimal number, but the converse may not be possible. It depends on the number of display space available on the screen.

No. As long you try to divide the circumference of a circle by the square of the radius of the circle, you'll get the ratio "pi".
Note that "pi" is a ratio, not a measurement in some units (inches? centimeters?), so it simply "is what it is", namely an irrational number.

Get the trouble code for the Ck eng light, then get back .