Well, this polynomial first has a difference of squares
inside
Mutiplying them
out
(a+b^2)(a-b^2)=a^2-b^4
The
whole polynomial
becomes
(a^2-b^4)^5
Using
Pascal's Triangle and the Binomial Theorem:
1
first degree
1 2 1 second
degree
1 3 3 1 third
degree
1 4 6 4 1 fourth
degree
1 5 10 10 5 1 fifth
degree
so the polynomial (a^2-b^4))^5= (a^2))^5-
5((a^2)^4))b^4 + 10
((a^2)^3)((b^4)^2)-10((a^2)^2)((b^4)^3)+5a^2((b^4)^4)+(b^4)^5
simplify
this huge expression
=
a^10-5(a^8)*(b^4)+10(a^6)*(b^8)-10(a^4)*(b^12)+5(a^2)*(b^16)-b^20
Actually,
for any polynomial to the exponent
5
(x+y)^5=x^5+5(x^4)*y+10(x^3)*(y^2)+10(x^2)*(y^3)+
5x*(y^4)+y^5
You
could see, the x-exponent is decreasing by one every term, and the y exponent is
increasing by one in every term.
The
coefficents are given by the Pascal Triangle.
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