How do you use the binomial series to expand #(x - y)^6#?
1 Answer
#color(green)(x^6-6x^5y+15x^4y^2-20x^3y^3+15x^2y^4-6xy^5+y^6#
Explanation:
#color(blue)((x-y)^6#
Let's use the pascal's triangle to solve it
So,
#underbracecolor(blue)((x-y)^6)#
#underbrace(color(indigo)(1)color(blue)((x^6)(-y^0))+color(indigo)(6)color(blue)((x^5)(-y^1))+color(indigo)(15)color(blue)((x^4)(-y^2))+color(indigo)(20)color(blue)((x^3)(-y^3))+color(indigo)(15)color(blue)((x^2)(-y^4))+color(indigo)(6)color(blue)((x^1)(-y^5))+color(indigo)(1)color(blue)((x^0)(-y^6))#
#underbrace(color(indigo)(1)color(blue)((x^6))-color(indigo)(6)color(blue)((x^5)(y))+color(indigo)(15)color(blue)((x^4)(y^2))-color(indigo)(20)color(blue)((x^3)(y^3))+color(indigo)(15)color(blue)((x^2)(y^4))-color(indigo)(6)color(blue)((x)(y^5))+color(indigo)(1)color(blue)((y^6))#
#color(green)(x^6-6x^5y+15x^4y^2-20x^3y^3+15x^2y^4-6xy^5+y^6#
To understand this better. Watch this