Q:

Let f(x) = n^2 - 1, where n is an integer and n >= 1. Is f(x) always divisible by (x - 1)? Justify.

Accepted Solution

A:
Answer:Yes.Step-by-step explanation:(Assume x is not 1.)[tex]\frac{x^n-1}{x-1}[/tex] is always divisible for integers greater than 1.Let's use synthetic division:1  |   1x^n     + 0x^(n-1)    +0x^(n-2) + ....+0x^3+0x^2+0x -1   |                  1                 1                      1         1        1     1 ---------------------------------------------------------------------------------       1              1                 1                      1         1         1      0We see the remainder is 0 which means that [tex](x-1)[/tex] divides [tex](x^n-1)[/tex].The quotient is [tex]x^{n-1}+x^{n-2}+x^{n-3}+\cdots+x^2+x+1[/tex].