1) Find all the zeros of the function: g(x)= x^3+3x^2-18x-40, given that one factor is (x+5) 2)Find all zeros of the function: g(x)= x^3+x^2-17x+15, given that one zero is x=1

Respuesta :

It is given that

[tex]g(x)=x^3+3x^2-18x-40[/tex]

The one factor of g(x) is (x+5).

By using the synthetic method, we get

[tex]g(x)=(x+5)(x^2-2x-8)[/tex]

[tex]g(x)=(x+5)(x^2-4x+2x-8)[/tex]

[tex]g(x)=(x+5)(x(x-4)+2(x-4))[/tex]

[tex]g(x)=(x+5)(x-4)(x+2)[/tex]

Hecne zeros of g(x) is -5,4, and -2.

2)

It is given that

[tex]g(x)=x^3+x^2-17x+15[/tex]

The one zero of the given g(x) is x=1.

By using the synthetic method, we get

[tex]g(x)=(x-1)(x^2+2x-15)[/tex]

[tex]g(x)=(x-1)(x^2+3x-5x-15)[/tex]

[tex]g(x)=(x-1)(x(x+3)-5(x+3))[/tex]

[tex]g(x)=(x-1)(x+3)(x-5)[/tex]

To find zeros of g(x) by equating g(x) to zero.

[tex]g(x)=(x-1)(x+3)(x-5)=0[/tex]

[tex](x-1)=0;(x+3)=0;(x-5)=0[/tex]

[tex]x=1;x=-3;\text{ x=5}[/tex]

Hence the zeros of the given function g(x) are 1,-3, and 5.

Ver imagen HannahgraceN688253
Ver imagen HannahgraceN688253