Thursday

March 5, 2015

March 5, 2015

Posted by **BioBabe** on Sunday, October 12, 2008 at 11:48pm.

P.S. Factor theorem does not work here.

- 12th grade Math? -
**drwls**, Monday, October 13, 2008 at 2:34amLook for the first root by trial and error. Using the "q/p theorem", I see that one solution is +1/3. So, (x - 1/3) is one factor.

Divide that into 3x^3-4x^2+4x-1 to get a quadratic factor,

(3x^2 -3x +3) = 3 (x^2 -x +1).

The term in parentheses can be factored by the usual means, but gives two complex roots.

3x^3-4x^2+4x-1 = 3(x- 1/3)(x^2-x+1)

(3x-1)(x^2-x+1))

- 12th grade Math? -
**BioBabe**, Monday, October 13, 2008 at 11:03amWhat's the q/p theorem though?

- 12th grade Math? -
**drwls**, Monday, October 13, 2008 at 12:03pmI was afraid you'd ask me that :-)

The more common name for it is the rational roots test (or theorem).

Here is a reference.

http://en.wikipedia.org/wiki/Rational_root_theorem

It doesn't always provide a root, but if there is a rational real root, it works.

Briefly, it says that if the constant term of the polynomial is q and the first term in p, and if there are rational real roots, one of the roots will be

+/- q/p or +/- the tio of prime-number factors of q and p.

- eapmo dzywoakr -
**eapmo dzywoakr**, Friday, February 6, 2009 at 12:26pmsmopnruj sdycgmrw ejtz lawycf hegycpt icvsw ampisx

**Answer this Question**

**Related Questions**

Using the factor Theorem - use the factor theorem to determine whether x-c is a ...

calculus-can someone please help me with this ques - I have two questions if ...

Math - Use the Factor Theorem to determine whether x-3 is a factor of P(x)=2x^3-...

math - use the remainder theorem an the factor theorem to determine whether (y-3...

college algebra - use the remainder theorem to find the remainder when f(x) is ...

Pre Calculus - using the factor theorem to show that x-c is a factor of P(X) for...

Maths (factor theorem) - 9x^2 6xy 4y^2 is a factor of 27x^3 - 8y^3, find the ...

Algebra - Use the Factor Theorem to determine whether x+2 is a factor of P(x)=2x...

Calculus - How can i factor x^3 - 3x^2 + x -4? I tried the factor theorem method...

math - factor x^4-3x^3-11x^2+3x+10 completely using the factor theorem.