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By Ramirez7 (Ramirez7) on Tuesday, April 01, 2003 - 01:05 am: Edit |

x2-4x+18=0

By Mrpancake2000 (Mrpancake2000) on Tuesday, April 01, 2003 - 08:48 am: Edit |

2 plus or minus 2i times the square root of 14, no?

By Dumbuket (Dumbuket) on Friday, April 04, 2003 - 04:14 pm: Edit |

umm... quadratic equation, u dumb fuhkahs!!!

By Bhs4life (Bhs4life) on Friday, April 04, 2003 - 04:15 pm: Edit |

x=9

By Zerg_Vvins (Zerg_Vvins) on Saturday, April 12, 2003 - 04:46 pm: Edit |

use this:

the answer is 4 plus or minus square root of -56 over 2

By Worth2try (Worth2try) on Tuesday, April 22, 2003 - 12:11 pm: Edit |

I got 9 too

By Brd (Brd) on Tuesday, April 22, 2003 - 12:34 pm: Edit |

If you got x=9, you should consider a review of algebra. In any event, it's always good to check your answers. It only takes a *glance* to see that:

81 - 36 + 18

cannot possibly equal zero.

Zerg has the correct answer. (MrPancake probably *had* the correct answer but made a mistake simplifying; he forgot to cancel a two in the second term.)

By Ashleycrombie (Ashleycrombie) on Wednesday, April 23, 2003 - 04:18 am: Edit |

x = 2 + squareroot18

or

x = 2 - squareroot18

By Ashleycrombie (Ashleycrombie) on Wednesday, April 23, 2003 - 04:21 am: Edit |

i meant 2 +/- squareroot(-14) in both

By Brd (Brd) on Wednesday, April 23, 2003 - 10:14 am: Edit |

Which is the same as Zerg's answer...

By Terpsfan (Terpsfan) on Thursday, April 24, 2003 - 03:28 pm: Edit |

Excuse me but the only right answer is mr. pancake. Zerg is wrong because you cannot take the root of a negative number. Not only that but the root of 56 can be simplified. You all need to brush up on your math skills, and it makes me wonder how many people on these posts actually lie about their test scores....

By Dxiw (Dxiw) on Thursday, April 24, 2003 - 06:23 pm: Edit |

zergs answer is right, it is simple an imaginary equation. That equation does not have any real solutions only imaginary ones. You solve using the quadratic formula:

ax^2+bx+c=0

a=1 b=-4 c=18

x=(-b + sqrt(b^2-4ac))/(2a)

x=(-b - sqrt(b^2-4ac))/(2a)

so...

x=(4 + sqrt(16-4*1*18))/(2*1)

x=(4 - sqrt(16-4*1*18))/(2*1)

so..

x=(4+sqrt(-56))/2

x=(4-sqrt(-56))/2

which when simplified is..

x=(4+2sqrt(14)i)/2

and..

x=(4-2sqrt(14)i)/2

for all you math morons, sqrt(56) = sqrt(14*4) = 2sqrt(14)

By Brd (Brd) on Thursday, April 24, 2003 - 06:24 pm: Edit |

*"Zerg is wrong because you cannot take the root of a negative number."*

Um, sure you can. You have to admit what are called complex numbers. Apparently you have not learned about them yet, which is ok. If you will notice, Mr. Pancake *also* takes the square root of negative 56, he just simplified it and pulled out the complex factor **i=sqrt(-1)**. But he forget to cancel the denominator in the second (imaginary) term so has an extra factor of 2 there.

Also, just to be pedantic, not simplifying something like *sqrt(56)* in an answer does not make the answer *wrong*. Not simplifying an answer might go against the instructions on some or other assignment, and cost you some "points", but that doesn't make the answer *incorrect*. Plug the unsimplified answer into the equation. You get zero. QED.

For the record, my second degree was in Mathematics. There are plenty of things I need to review; basic algebra is not one of them.

By Vizious (Vizious) on Thursday, April 24, 2003 - 06:44 pm: Edit |

does x2 mean 2x or x^2

if x2 was viewed as 2x, the answer would come out to nine

By Brd (Brd) on Thursday, April 24, 2003 - 07:05 pm: Edit |

Sure, but no one would ever write *2x* as *x2*. If you were giving a talk at a seminar and did that I can gaurantee you dirty looks from across the room. I think the consensus is that *x2* is an attempt to express *x ^{2}* (

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