Factorize and 簡化

1) 1-2sinxcosx-tan^2x
= sin^2x-2sinxcosx+cos^2x - tan^2x
= (sinx-cosx)^2 - tan^2x
=(sinx-cosx+tanx)(sinx+cosx+tanx)

2) x^8-256 / x^6+4x^4+16x^2+64
= (x^4-16)(x^4+16)/ (x^2+4)(x^4+16)
= (x^2+4)(x^2-4)/(x^2+4)
=x^2-4
=(x-2)(x+2)