Question 115318
having problems fiquring out how i(1+i)^3 *(1-i) is equal to -4
------------------------------
Expand:
i[1^3+3i+3i^2+i^3]*(1-i)

= i[1 + 3i -3 -i]*(1-i)

= i[-2+2i](1-i)

= -2i[1-i](1-i)

= -2i[1-2i-1]

= -2i[-2i]

= -4
=============
Cheers,
Stan H.