How do you factor a^6 + 7a^3 + 6?
2 Answers
Explanation:
Call
Since a - b + c = 0, use shortcut. One factor is (x + 1) and the other is
Replace x by a^3.
Factor
Finally,
a^6+7a^3+6=(a+1)(a^2-a+1)(a+root(3)(6))(a-root(3)(6)a+root(3)(36))
Explanation:
First treat this as a quadratic in
So:
a^6+7a^3+6 = (a^3)^2+7(a^3)+6 = (a^3+1)(a^3+6)
Note that both
A^3+B^3 = (A+B)(A^2-AB+B^2)
with
(a^3+1) = (a^3+1^3) = (a+1)(a^2-a+1)
The factor
(a^3+6)
= (a^3+(root(3)(6))^3)
= (a+root(3)(6))(a-root(3)(6)a+(root(3)(6))^2)
= (a+root(3)(6))(a-root(3)(6)a+root(3)(6^2))
= (a+root(3)(6))(a-root(3)(6)a+root(3)(36))
Putting this together:
a^6+7a^3+6=(a+1)(a^2-a+1)(a+root(3)(6))(a-root(3)(6)a+root(3)(36))
This is as far as we can go with Real numbers.