How do I factor this polynomial?
\[a ^{6}+b ^{3}\]
is that a^6?+b^2?
b^3
\[a^6 + b^3= (a^2+b)(a^4+b^2-a^2b)\] I have used this formula \[x^3+y^3 = (x+y)(x^2-xy+y^2)\]
I don't get the formula..
and how it fits the problem.
do you remember the difference of squares factorization i gave earlier? it is only 1 of mostly three you need to "memorize"... look at page 2, the fatoring formulas here: http://tutorial.math.lamar.edu/pdf/Algebra_Cheat_Sheet.pdf
the one he gave is called the sum of cubes fromula: \(\large a^3+b^3=(a+b)(a^2-2ab+b^2) \)
Right @dpaInc Very correct and a nice cheat sheet
notice you can write \(\large a^6=(a^2)^3 \) so now you actually have a sum of cubes: \(\large (a^2)^3+b^3 \)
Yup, but there's more to that right?
just use the formula now....
i don't think there's more to it...
:)
why does the a become a a^4?
because now your a is actually a^2... so when you plug it into the formula (a^2)^2 = a^4
if i were to ask you to factor this: \(\large z^3+b^3 \) would you be able to?
Why does the b become a b^2 when the formula says to multiply?
ok... hang on....
I'm not sure. I don't think I would be able to.
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