The graph of quadratic function f(x) has a minimum at (-2,-3) and passes through the point (2,13). The function g(x) is represented by the equation
g(x) = -(x+2)(x-3).

How much greater is the y-intercept of g(x) than f(x)?

Respuesta :

Answer:

The y-intercept of g(x) is 5 greater than the y-intercept of f(x).

Step-by-step explanation:

It is given that the graph of quadratic function f(x) has a minimum at (-2,-3) and passes through the point (2,13).

The equation of a quadratic function is

[tex]f(x)=a(x-h)^2+k[/tex]

Where, (h,k) is vertex or extreme points and a is stretch factor.

The minimum value of function is (-2,-3), so the vertex is (-2,-3).

[tex]f(x)=a(x-(-2))^2+(-3)[/tex]

[tex]f(x)=a(x+2)^2-3[/tex]

It is given that the function passing through the point (2,13).

[tex]13=a(2+2)^2-3[/tex]

[tex]16=16a[/tex]

[tex]a=1[/tex]

So, the function f(x) is

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

Substitute x=0, to find the y-intercept.

[tex]f(x)=(0+2)^2-3[/tex]

[tex]f(x)=4-3=1[/tex]

The y-intercept of f(x) is 1.

The given function is

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

Substitute x=0, to find the y-intercept.

[tex]g(x)=-(0+2)(0-3)=6[/tex]

The y-intercept of g(x) is 6.

The difference between y-intercepts is

[tex]6-1=5[/tex]

Therefore y-intercept of g(x) is 5 greater than the y-intercept of f(x).

ANSWER

The y-intercept of g(x) is 5 greater than f(x)?

EXPLANATION
The function f(x) has a minimum at (-2,-3) and passes through (2,13).
The equation in vertex form is given by,

[tex]f(x)=a {(x - h)}^{2} + k[/tex]

[tex]f(x)=a {(x + 2)}^{2} - 3[/tex]

We substitute (2,13) to find the value of a,

[tex]13=a {(2 + 2)}^{2} - 3[/tex]

[tex]a {(4)}^{2} = 16[/tex]

[tex]a = \frac{16}{16} [/tex]

[tex]a=1[/tex]

[tex]f(x)={(x + 2)}^{2}-3[/tex]

The y-intercept is

[tex]f(0)={( 2)}^{2} - 3 =1[/tex]

Also,

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

has y-intercept,

[tex]g(0) = - (0+ 2)(0 - 3) = 6[/tex]

The difference is

[tex]6 -1= 5[/tex]