Factorising cubed roots?! (1 Viewer)

Brock1 · Feb 13, 2016

How would I solve these questions? Thanks in advanced

InteGrand · Feb 13, 2016

Brock1 said:
How would I solve these questions? Thanks in advanced

$\noindent Use the factorisation rules $A^3 \pm B^3 = \left(A \pm B\right) \left(A^2 \mp AB + B^2\right).$

Brock1 · Feb 13, 2016

How would i apply these to the trinomials?

InteGrand · Feb 13, 2016

Brock1 said:
How would i apply these to the trinomials?

$$\noindent These aren't trinomials, they are simply cubes (they are also expandable via the binomial theorem). Expanding things like $\left(a_1 + a_2 + a_3\right) ^n$ is done via the trinomial theorem (a generalisation of the binomial theorem, and special case of the multinomial theorem). A binomial expansion is the expansion of something like $\left(a_1 + a_2 \right)^n$. In general, a \textit{multinomial} expansion would be the expansion of something like $\left(a_1 + a_2 +\cdots + a_r \right)^n$.$

$\noindent For these questions, just set one of the cubes to be $A$, and the other $B$, then use the factorisation formulae in my previous post.$

Shuuya · Feb 13, 2016

This should be the factorisation of the first one, you should be able to do the second one in the same way, as InteGrand said

Factorising cubed roots?! (1 Viewer)

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