How Are Solutions -91.9 and 170 Derived Using the Quadratic Formula?

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Homework Help Overview

The discussion revolves around the evaluation of a quadratic formula expression, specifically the calculation of solutions derived from the expression -1±√11.24/-0.0256. The original poster expresses confusion regarding the solutions -91.9 and 170 provided by the instructor.

Discussion Character

  • Exploratory, Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the correct evaluation of the quadratic formula, suggesting the separation of terms and the importance of proper parentheses. There is also a focus on ensuring the accuracy of calculator inputs.

Discussion Status

Some participants have offered guidance on evaluating the expression correctly, emphasizing the need for clarity in the calculation process. The original poster acknowledges a misunderstanding in their approach, indicating a shift towards a more accurate evaluation.

Contextual Notes

There is mention of potential confusion arising from the format of the quadratic formula and the calculations involved, as well as the original poster's initial method of evaluation which led to incorrect results.

Kimosabae
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Could someone please help with this evaluation?

Homework Statement



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