Question:
Using factor theorem, show that g(x) is a factor of p(x), when
$p(x)=x^{3}-8, g(x)=x-2$
Solution:
Let:
$p(x)=x^{3}-8$
Now,
$g(x)=0 \Rightarrow x-2=0 \Rightarrow x=2$
By the factor theorem, (x – 2) is a factor of the given polynomial if p(2) = 0.
Thus, we have:
$p(2)=\left(2^{3}-8\right)=0$
Hence, $(x-2)$ is a factor of the given polynomial.