# Quadratic Formula Evaluation

1. Jul 23, 2013

### Kimosabae

Could someone please help with this evaluation?

1. The problem statement, all variables and given/known data

-1+/-√11.24/-0.0256

The solutions given for this are -91.9 and 170 and I am truly flabbergasted as to how this instructor achieved these values.

2. Jul 23, 2013

### SteamKing

Staff Emeritus
The way you have written the quadratic formula may be confusing you.

Try evaluating (-1 + SQRT (11.24))/(-0.0256) and (-1 - SQRT (11.24))/(-0.0256) separately.

If you don't get -91.9 and 170 respectively, your calculator is broken or you are doing something wrong punching in the numbers.

3. Jul 23, 2013

### collinsmark

And don't forget the proper parenthesis.
$$\frac{\left(-1 \ \pm \sqrt{11.24} \ \right)}{-0.0256}$$

4. Jul 23, 2013

### Kimosabae

Thanks so much, gentlemen. I was evaluating incorrectly. I was trying to put -0.0256 over 1 to get rid of the fraction, multiply by the -1 and then add +0.0256 to +/-√11.24 giving me the incorrect values. Thanks again!

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