Reciprocals, Exponents and RadicalsReference > Mathematics > TI-30X II
There is a special key just for squaring a number. It looks like this: x2. If you wanted to square the number 7, you would press 7, followed by the SQUARE button. Press ENTER to see the result.
But what if you want to raise seven to the third power, instead of squaring it? Well, this is almost as easy. Find the caret button (a caret looks like this:</strong>). Now press: 7 3 = and you will see the result: 343.
A reciprocal is a special power; it's a number raised to the -1 power. It's also what you get by swapping the numerator and denominator. There is a special key for reciprocals. It's the x-1 key.
So let's find the reciprocal of 5. We press 5 x-1 = , and we get an answer of 0.2.
There is also a special key for taking a square root. It's the 2nd function of the SQUARE button. If you want to take the square root of 81, press 2nd SQUARE 81 =, and the calculator will show you the result: 9.
I hope you noticed that there is an open parenthesis between the square root sign and the number 81. This means that until you put a close parenthesis, everything is considered to be part of the square root. If you never hit a close parenthesis, when you hit enter, the calculator assumes that you meant to put the parenthesis at the end of what you typed.
Why is this important? Consider the following:
Notice that in one of those I put a close parenthesis and in the other I didn't. Try entering both of those into your calculator. Do they give the same result?
Parentheses are important!
Can you take a cube root? Absolutely! Or a fourth root. Or a fifth root. You can even take 1/3 roots if you really wanted to!
Find the caret key, and notice that an x-root symbol is directly above it. You know what that means! It's the 2nd function.
So suppose you wanted the cube root of 64. Here is what you would type:
3 2nd 64 =
The result is 4.