Left alpha - Right beta triangle
This graph shows graph of [z=(x^n-y^n)/(x-y)].
when n=1, z=1
n=2, z=x+y
n=3, z=x^2+xy+y^2
n=4, z=x^3+x^2y+xy^2+y^3
...
these form can expressed by this triangle 'Left alpha - Right beta triangle'
1
α β
α^2 αβ β^2
α^3 α^2β αβ^2 β^3
...
cf)This graph shows triangle too, when n=2