Tuesday

September 23, 2014

September 23, 2014

Posted by **jerroyle** on Friday, August 23, 2013 at 9:28am.

- math -
**Steve**, Friday, August 23, 2013 at 12:39pma^4-7a^2+9

a^2 = (7±√13)/2

Now it gets tricky:

7+√13 = (1+2√13+13)/2 = (1+√13)^2/2

So, if

a^2 = (7+√13)/2 = (1+√13)^2/4

a = ±1/2 (√13+1)

and

a = ±1/2 (√13-1)

Makes things kind of nasty, the factors are

1/16 (±2x + √13 ± 1)

where all 4 combinations of + and - are used.

- math -
**MathMate**, Friday, August 23, 2013 at 12:40pmHint:

substitute u=a^2, then

a^4-7a^2+9

=u^2-7u+9

and try to factorize.

However, check you question to see if there is a typo. The above expression in u does not have rational factors.

**Answer this Question**

**Related Questions**

math - If the sides of a box all double in length, by how much does its volume ...

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

stats - two factor ANOVA indep measures exper. 2 level factor A 3 level factor B...

math - Is 3 a factor of 261? Is 10 a factor of 325? Is 6 a factor of 492?

Math - Factor Completely: I am really confused on how to start it. 12q^5w^2-36q^...

math - The graph of f (x)₌√x undergoes a vertical stretch by a ...

Factor - How do I factor these: 2x2 - 16x + 30 4x^2-9 x^2-5x 5x^2-26x+5 25x^2+4 ...

factoring - how to factor x^4 - 2x^3 - 8x + 16 Thanks. you can factor by ...

Math finance - I just brought a finanical calculator and i don't really know how...

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