Multiply x2 + x + 1 by x2 - x + 1
A
x4 - x + x2
B
x4 - x2 + x2
C
x4 + x2 + 1
D
x4 + x2
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
(x2 + x + 1)( x2 - x + 1)
= x2(x2 + x + 1) - x(x2 + x + 1) + (x3 + x + 1)
= x4 - x3 + x2 + x3 - x2 - x + 1
= x4 + x2 + 1
Source: Myschool Past Questions Archive (Record #32598)