x^6 -1 factorise it...?
Answers
Answered by
5
hiii
x^6-1=(x^3)2-(1)^2
and we know a^2-b^2=(a+b)(a-b)
so
here
(x^3-1)(x^3+1)
also,a^3-b^3=(a-b)(a^2+b^2+ab)
and a^3+b^3=(a+b)(a^2+b^2-ab)
so,
using that identity
we can further expand it as
(x-1)(x^2+1+x)(x+1)(x^2+1-x)
easiest question✔️✔️
Answered by
6
To factorise:
- x^6 - 1 = 0
Solution:
[Using algebraic identity
- a^2 - b^2 = (a + b) (a - b)]
➡ x^6 - 1
➡ ((x)^3)^2 - (1)^2
➡ (x^3 + 1) (x^3 - 1)
[Now, Using algebraic identities
- a^3 + b^3 = (a + b) (a^2 + b^2 - ab)
and
- a^3 - b^3 = (a - b) (a^2 + b^2 + ab)]
➡ (x^3 + 1^3) (x^3 - 1^3)
➡ (x + 1) (x^2 + 1^2 - x(1)) (x - 1) (x^2 + 1^2 + x(1))
➡ (x + 1) (x^2 - x + 1) (x - 1) (x^2 + x + 1)
Factorised.
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