find the x intercept for 3x^5 - 7x^2 + 2

[momina4468]

Can someone find the x intercept for 3x^5-7x^2+2.....How would you factor it? I know the y intercept is 2

 

[Deleted member 4993]

Re: help with this polynomial plz

Can someone find the x intercept for 3x^5-7x^2+2.....How would you factor it? I know the y intercept is 2

Do you know rational root test?

If not, please review at:

http://www.purplemath.com/modules/rtnlroot.htm

However, looking at the plot - it seems that this function has three real roots - but may be none of those are rational.

Otherway is to use numerical method like Newton-Raphson's Method.

 

[momina4468]

Re: help with this polynomial plz

ok well the possible roots are plus and minus (1,2,2/3,and 1/3) and when i plug them into the polynomial, none of them equal zero

 

[Denis]

Re: help with this polynomial plz

ok well the possible roots are plus and minus (1,2,2/3,and 1/3)......

Says WHO?

 

[mmm4444bot]

Re: help with this polynomial plz

ok well the possible roots are plus and minus (1,2,2/3,and 1/3)

and when i plug them into the polynomial, none of them equal zero



So, what does this tell you about the nature of the roots?

MY EDIT: Deleted incorrect list of possible rational roots, as well as my false conclusion. (Thank you, Subhotosh)

 

[Deleted member 4993]

Re: help with this polynomial plz

Okay - may be I am misinterpreting something -

Mark - why aren't you considering 1 as a factor in the denominator?

 

[mmm4444bot]

Re: help with this polynomial plz

Mark - why aren't you considering 1 as a factor in the denominator?

Hi Subhotosh:

Now, I am.

(Two things that I know that I should never do, but seem to keep doing anyway, are math in my head and math while enjoying wine in my head.)

I will send a private message to the original poster. Thank you, Subhotosh.