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Topic: quadratic formula  (Read 1555 times)

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Offline yanna.banana

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quadratic formula
« on: June 27, 2016, 04:23:22 PM »
can someone give me a step by step walk through of this

here is my equation 0=x^​2​​ +6.3*10^​−8x−1.0*10^−14
 the answers are 7.3*10^-8 and -1.4*10^-7
i keep obtaining
6.3*10^-8 +/- 2.01*10-7 divided by 2 giving me
2.64*10^-7 and -1.38*10^-7
​​

Offline Borek

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Re: quadratic formula
« Reply #1 on: June 27, 2016, 05:50:59 PM »
6.3*10^-8 +/- 2.01*10-7 divided by 2 giving me
2.64*10^-7 and -1.38*10^-7​

No way to reproduce these numbers. I suspect you are misusing your calculator.

Note: the correct formula calls for -b, not b (so (-6.3×10-8±2.10×10-7)/2).
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Offline yanna.banana

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Re: quadratic formula
« Reply #2 on: July 01, 2016, 11:27:44 AM »
okay then it must be a copying error my issue is i never am able to solve this quadratic properly.
i have  right now (for a different question)
0= x^2-1.74*10^-6 + 10^-4.76x

i am obtaining  +4.17*10^-3 and - 4.17*10^-3 and it is not correct.
Can someone show me a step by step?
thanks it would be so helpful.. i think the scientific notation is throwing me off. as i can solve with regular numbers

Offline mjc123

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Re: quadratic formula
« Reply #3 on: July 01, 2016, 11:36:30 AM »
Why don't you show us step by step how you got those numbers? We could go through it for you, but if your problem is that you are entering it into a calculator incorrectly, that won't help you.

PS Did you use 1.74 x 10-5 instead of 1.75 x 10-6?

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