Verify in the following whether g(x) is a factor of p(x)
(i). g(x) = x-2; p(x) = x⁴-x³-x²-x-2
(ii). g(x) = x+1; p(x) = 2x³+x²-2x+1​

Respuesta :

[tex] \red{\large\underline{\sf{Solution-i}}}[/tex]

Given that,

[tex] \rm \longmapsto\: p(x) = {x}^{4} - {x}^{3} - {x}^{2} - x - 2[/tex]

and

[tex]\rm \longmapsto\:g(x) = x - 2[/tex]

We know,

Factor theorem states that if g(x) = x - a is a factor of polynomial f(x), then remainder f(a) = 0.

So, using Factor theorem, Consider

[tex]\rm \longmapsto\:p(2)[/tex]

[tex]\rm \:  =  \: {2}^{4} - {2}^{3} - {2}^{2} - 2 - 2[/tex]

[tex]\rm \:  =  \: 16 - 8 - 4 - 4[/tex]

[tex]\rm \:  =  \: 16 - (8 + 4 + 4)[/tex]

[tex]\rm \:  =  \: 16 - 16[/tex]

[tex]\rm \:  =  \: 0[/tex]

[tex]\rm\implies \:p(2) \: = \: 0[/tex]

So,

[tex]\bf\implies \:g(x) \: is \: factor \: of \: p(x)[/tex]

[tex] \red{\large\underline{\sf{Solution-ii}}}[/tex]

[tex]\rm \longmapsto\: p(x) = 2{x}^{3} + {x}^{2} - 2x + 1[/tex]

and

[tex]\rm :\longmapsto\: g(x) = x + 1[/tex]

Now, By using Factor Theorem, Consider

[tex]\rm \longmapsto\:p( - 1)[/tex]

[tex]\rm \:  =  \: 2 {( - 1)}^{3} + {( - 1)}^{2} - 2( - 1) + 1[/tex]

[tex]\rm \:  =  \: - 2 + 1 + 2 + 1[/tex]

[tex]\rm \:  =  \: 2[/tex]

[tex]\rm\implies \:p( - 1) \: \ne \: 0[/tex]

So,

[tex]\bf\implies \:g(x) \: is \: not \: a\: factor \: of \: p(x)[/tex]