Discussion in 'Off Topic' started by Liam W, Oct 4, 2013.
I've added this to my signature...
Got the solution? I'm doing it in school...
Yep, got the solution but just in case this is one of your school problems I'd best not give you the answer.
All I will say is complex numbers, nice.
I literally made it up on the spot while typing it out into the signature box
I better had complete it now, so I know if other's get it right!
Oh OK, I believe you.
or if you prefer it written 'correctly' as a complex number,
x=42 Everything always equals 42
What's i ?
i is the square root of -1.
Isn't it actually x = -1 +/- i?
Liam, I assume you're doing quadratic equations at school?
Set the two expressions you've been given as being equal (as you're told in the question) and then get it into the form 0 = ax^2 + bx + c
The use the quadratic formula to get the value of x.
Yes, you are correct,
because of course sqrt of -1 is indeed either -i or +i
Erm no...I actually meant because the quadratic formula is (-b +/- sqrt(b^2-4ac))/2a. You only did the + part of that.
Yes of course! Though (-i)^2 and i^2 both equal sqrt -1, you are correct that it is from the quadratic equation that you get both of the answers for x.
*EDIT* Actually were both correct. You just did it using the quadratic formula to calculate the answer. I did it from the quadratic equation and resolving as far as x=-1 + sqrt(-1) I just forgot that sqrt(-1) has two answers, -i and +i. What the quadratic formula reminds us of is that there are two answers to any sqrt, the positive and the negative hence ± in the formula.
I've given this a lot of thought and I've come to the conclusion that x = bacon.
That's easy... x = the 24th letter of the english alphabet.
Oh man, I don't miss Calculus. So glad I'm almost done with my math credits.
Well done all
I did this on paper last night... I forgot to change the minus to a plus on the 10 when transferring it over
5x^2+12x = 2(x-5)
5x^2+12x = 2x-10
x=-10+sqrt(-100)/10 OR x=-10-sqrt(-100)/10
x=-10+10i/10 or x=-10-10i/10
x=-1+i or x=-1-i
While I liked math, can't say I miss this stuff. I can say I have never had to do a quadratic equation in the 10 years I spent as a project engineer, then director of engineering. (Or 5 years since.)
I'll be honest and say I've absolutely no idea whatsoever ...
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