Can someone explain this I honestly have no idea how to find the freaking answer.

Question

luckylu · Answer

What are the possible numbers of positive, negative, and complex zeros of 
f(x) = x^6 + x^5 + x^4 + 4x^3 − 12x^2 + 12?

luckylu · Answer

$$f(x)= x^6+ x^5+ x^4 +4x^3-12x^2 +12$$

luckylu · Answer

@retirEEd

retireed · Answer

There is a way of determining answer by analyzing the value of the largest power (ie 6) and looking at the number of sign changes (ie + to - or - to +, in this problem there are two sign changes), but I don't know ow to determine if the roots are real or complex.

I will looking on google and see if I can find the method again or do you know it?

luckylu · Answer

I don't know how to do it lol I finished the lesson about 1 1/2 weeks ago and can't remember a thing

retireed · Answer

It is called Descartes' Rule.  You can google and look at it will I try to re-learn it, too.

I will have to leave pretty some to walk my dog.  I don't want to clean up any poo poo.

luckylu · Answer

Okay that's fine thank you.

retireed · Answer

I will be back in about an hour.  Rex likes long walks.

retireed · Answer

Sorry I was gone so long.  I hope you figured it out, but in case you didn't.  Here is what I think the answer might be...

I don't know if graphed roots are positive or negative depending on which side of the x-axis they fall on.  I need to run an example that I know the roots for. 

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