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Homework Statement
How do I find the roots of 4x^3+x+5 = 0? It doesn't appear to be in a nice form like many equations in the textbook?
No problem, don't worry bout it, your a new member so we won't send you to the gallows just yet :tongue: . Seriously though, any help that you can give in the forums is very much appreciated. Welcome to the Forums!Feldoh said:Sorry, and on the downside, apparently I can't add :(
Hootenanny said:No problem, don't worry bout it, your a new member so we won't send you to the gallows just yet :tongue: . Seriously though, any help that you can give in the forums is very much appreciated. Welcome to the Forums!
That simplifies to 4(+/-)/[square root of 8]i/8
This answer is actually correct, I missed the minus sign in my previous post (typo sorry ), you must have made a mistake in your previous method. As an aside completing the square is equivalent to using the quadratic equation (in fact the quadratic equation is derived by completing the square)pugfug90 said:Oopd.. Forgot to take the square root after de squaring 64 :D
Is there any way to simplify 4x^2 + 4x + 5 besides quadratic formula?
I tried completing the square..
4x^2 + 4x + 5..
4(x^2 + x)=-5
(x^2 + x)=-5/4
(x^2 + x + 0.25)=-1
(x+0.5)^2=-1
x+0.5=(+/-)i
x=-0.5 (+/-)i..
I got real close.. then got that -0.5 at the end..
pugfug90 said:
For the real Polynomial:
+4x^2+4x+5
The Solutions are:
X1=(-0.5+i1)
X2=(-0.5-i1)
pugfug90 said:How come putting the original 4x^3+x+5 doesn't decompose into -0.5..?