How do you expand $(y-x^2)^3$ ?

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Answer 1 · 2016-07-06T11:41:02

$y^3-3x^2y^2+3x^4y-x^6$

You can expand by using the identity:

$(a+b)^3=a^3+3a^2b+3ab^2+b^3$

So, in this case, it is:

$(y-x^2)^3=y^3+3y^2(-x^2)+3y(-x^2)^2+(-x^2)^3$

$=y^3-3x^2y^2+3x^4y-x^6$

How do you expand (y-x^2)^3(y-x^2)^3?