Plus or Minus Sign

Minus and change-sign are two completely different things. Minus is used to subtract one number from another. When you press minus when the input line is empty, your telling the calculator to subtract. The only way it can subtract the number you're about to put in is to subtract it from something else, and that something else is the previous answer, hence the "Ans."

If you want to input a negative number, use the change-sign key. If you want to subtract one number from another number, use the minus key.

Try pressing the plus key when the input line is empty. You'll get Ans+ in this case as well, The same with multiply and divide, among others, and for the same reason.

What are you trying to do?
Could it be that you entered a + sign followed by a - (minus) sign instead of a change sign (-). +-10

Make sure that it is a negative sign and not the minus sign. The answer by the way is about 6.09787589

Hello
You might want to check if the function has been entered properly. It should be something like this: "Y1 = X^2 + 2X + 4".
One of the most common errors is the use of the minus ( - ) sign. If you use the minus sign that's at the bottom of the calculator you're setting a negative number, not making a substraction.
Good Luck!

The calculator cannot handle "plus or minus" in the same equation. If you need both, enter two equations into y=, one for plus and the other for minus.

Hello,
The calculator has two minus signs

1. The regular MINUS sign which is used with the subtraction operation. This operation is binary, requiring two operands (two terms). In a-b, a and be are the operands (they very specific names, but I will skip this detail).
   
2. The negation or change sign. This operation is called unary, requiring one operand. -a means take the negative of the number a.

These are the technicalities, in which you may not be interested. On calculators, the two operations are implemented differently, with two signs, the regular minus sign -- , and the change sign (-) usually smaller in size than the regular -- sign and raised above the main line.

Examples. Let (-) be the negation and -- the regular minus.

• If you enter (-) 12 the TI84Plus accepts it and calculates the negative of 12.
• If you enter 12 (-) 13 the TI protests with a syntax error
• If you enter 12 ( (-) 13) the calculator interprets it as 12* (-13) and calculates -156.
• If you enter --12, the calculator displays Ans--12, where Ans is the last result calculated. If Ans happens to be 0, the new result is obviously the one you are expecting. But if Ans holds a non zero value, this is incorrect.

Suppose you have to calculate X^(-2)*X^(-1/3)
You can enter it exactly as it is written above. In this case, you must use the change sign (-) in both factors.
You can also decide to use the power rules and enter the expression as X^( -2 --1/3). In this case the first minus is the negation and the second is the regular minus.

I could go on with a few more examples, but that will take us away from your present concern.

In short.

1. If the minus sign is the leftmost (first) symbol in your function (after the Y1=) you should use the negation. Any subsequent minus should be the regular minus --
2. If the minus sign is the first symbol in an exponent, you must use the negation. Any subsequent minus in the expression of an exponent should be the regular minus --

I hope it did not bore you death with details you do not care to know about. I do hope that it will help you prevent this type of syntax errors.

Do not forget to rate the solution

Hi,
You cannot use the ± in the definition of a function. If you need to consider two alternatives, you have draw each function separately, one function as Y1 and the other as Y2. I just checked the catalog of commands, and there is no ±.

Hope it helps.
Thanks for using FixYa

Hello,
I am not sure what the cross (x) means: is it a multiplication or the variable x, so I took a screen capture of both cases.

The top case is obtained as follows the asterisk is the multiplication sign to thr right of digit 9; the small minus is the change sign key the minus sign in parentheses under digit 3 and to the left of ENTER key.; the forward slash is the division sign, above the multiplication sign.
This small minus called change sign makes a positive number negative and a negative number positive, hence its name. If your expression starts with a negative sign that is the one to use. Use it also for negative exponents.

As you can see the result is -.8. Notice how the - before the dot is small with respect to the regular minus, as in the last expression.

For the last expression on the screen capture, there is nothing special, except that you have two ways to enter the variable X.

1. Press [ALPHA] [STO->]
2. Press the key [X,T, Theta, n] to the right of the green [ALPHA] key.

Hope it helps.



If x is the multiplication sign
8[x] [(] (-)1

Its a little strange. Suppose you want subtract 10 from 38. Do this:
Enter 38 press plus key.
Enter 10, press minus key.
Press the equal sign. You will have the result.

try changing the back up battery also. This generally helps. The next time you change your batteries, change them one at a time. don't take them all out at once. This won't happen if you do it like that.