Find all rational zeros:
F(x)=x^4-7x^3+3x^2+21x-18

Question

Find all rational zeros: 
F(x)=x^4-7x^3+3x^2+21x-18

misty1212 · Answer

really?

misty1212 · Answer

how are you supposed to find the zeros of a fourth degree polynomial?

anonymous · Answer

What

anonymous · Answer

I have no idea. It's the problem my teacher gave me though....

misty1212 · Answer

lol ok apparently this factors as 
$$(x-1) (x-6) (x^2-3)$$

misty1212 · Answer

you know how i know it?

misty1212 · Answer

http://www.wolframalpha.com/input/?i=x%5E4-7x%5E3%2B3x%5E2%2B21x-18

anonymous · Answer

THANK YOU

jhannybean · Answer

Lol.

anonymous · Answer

Well if you don't know the steps the answer is useless...we can do division with (x-1) as it's a factor which then we end up with $$(x^3-6x^2-3x+18)(x-1) $$ you can factor out common terms and get the result misty provided which is $$(x-6)(x^2-3)(x-1)$$

anonymous · Answer

Thanks

anonymous · Answer

Note (x-1) is a facto because we let x = 1, which would give us 0 for f(1), hence it is a factor, and we can do the long division.