given the functions f(x) = x^2 and g(x) = 3x-2, determine how the vertex of the composite function would differ between (fg)(x) and (gf)(x)

Respuesta :

Answer:

The vertex of [tex]f\:\circ \:\:g(x)=(\frac{2}{3},0)[/tex]

The vertex of [tex]g\:\circ \:\:f(x)=(0,-2)[/tex]

Step-by-step explanation:

Given : Functions  [tex]f(x) = x^2[/tex] and  [tex]g(x) = 3x-2[/tex]

To determine : How the vertex of the composite function would differ between (fg)(x) and (gf)(x)          

Solution : First we find the composite function

[tex]f(x) = x^2[/tex] and  [tex]g(x) = 3x-2[/tex]

1) [tex]f\:\circ \:\:g(x)[/tex]

For  [tex]f(x) = x^2[/tex] substitute x with  [tex]g(x) = 3x-2[/tex]

[tex]f\:\circ \:\:g(x)=(3x-2)^2[/tex]

[tex]f\:\circ \:\:g(x)=9(x-\frac{2}{3})^2[/tex]

Vertex form is [tex]y=a(x-h)^2+k[/tex]

Comparing with  [tex]f\:\circ \:\:g(x)[/tex]

a=9, vertex [tex](h,k)=(\frac{2}{3},0)[/tex]

Therefore, The vertex of   [tex]f\:\circ \:\:g(x)=(\frac{2}{3},0)[/tex] ........[1]

2) [tex]g\:\circ \:\:f(x)[/tex]

For [tex]g= 3x-2[/tex] substitute x with  [tex]f(x) = x^2[/tex]

[tex]g\:\circ \:\:f(x)=3x^2-2[/tex]

To find the vertex of a quadratic function [tex]y=ax^2+bx+c[/tex] the vertex is [tex](-\frac{b}{2a},f(\frac{b}{2a}))[/tex]

Comparing with [tex]g\:\circ \:\:f(x)[/tex]

a=3 b=0,c=-2 substitute value,

[tex](-\frac{b}{2a},f(\frac{b}{2a}))=(0,-2)[/tex]

Therefore, The vertex of [tex]g\:\circ \:\:f(x)=(0,-2)[/tex] ...........[2]

Hence, The vertex of the composite function differ between [tex]f\:\circ \:\:g(x)[/tex] and [tex]g\:\circ \:\:f(x)[/tex] by [1] and [2]