The population of mosquitoes in a certain area as a function of inches of rainfall is modeled in the table. The function is quadratic,

RAINFALL(in.) .POPULATION (millions.)
0. . 0
1. . 9
3. . 21
4. .24
5. . 25
6. . 24

The x-intercept represents that after _____ in. of rain there are mosquities.
( I cant seem to wrap my head around this, If you can just help me start somehwere i'd really appriciate it. Also I noticed the pattern in mosquitoes.)

Respuesta :

Answer:

The x-intercept represents that after 10 in. of rain there are mosquitoes.

Step-by-step explanation:

The population of mosquitoes in a certain area as a function of inches of rainfall is modeled in the table.

The function is quadratic, [tex]P(x)=ax^2+bx+c[/tex]

where, P represents number of mosquitoes in millions. x represents rainfall in inches.

Table :

   x  :   0       1       3       4       5       6  

  P   :  0       9      21      24     25    24

Using three point to make system of equation and solve for coefficients a, b and c

Put (0,0) and we get  [tex]c=0[/tex]

Put (1,9) and we get [tex]a+b+c=9[/tex]

Put (3,21) and we get [tex]9a+3b+c=21[/tex]

Solve for a, b and c

[tex]a=-1[/tex]

[tex]b=10[/tex]

[tex]c=0[/tex]

[tex]P(x)=-x^2+10x[/tex]

Now, we will find x-intercept of the function. Put P(x)=0 and solve for x

[tex]-x^2+10x=0[/tex]

[tex]x=0,10[/tex]

The x-intercepts represent number of mosquitoes after 10 in of rain fall.

The x-intercept represents that after 10 in. of rain there are mosquitoes, when the population of mosquitoes in a certain area as a function of inches of rainfall.

What is a quadratic equation?

A quadratic equation is the equation in which the unknown variable is one and the highest power of the unknown variable is two.

The population of mosquitoes in a certain area as a function of inches of rainfall is modeled in the table.

  • RAINFALL(x in.)    POPULATION f(x) (millions.)
  •        0                        0
  •        1.                        9
  •        3                        21
  •        4.                       24
  •        5.                       25
  •        6.                       24

The function is quadratic. The standard form of the quadratic equation is,

[tex]f(x)=ax^2+bx+c[/tex]

Here (a,b, c) is the real numbers and (x) is the variable. For the first point (0,0). The equation become,

[tex]f(0)=a(0)^2+b(0)+c\\0=c[/tex]

For the second point (1,9). The equation become,

[tex]f(1)=a(1)^2+b(1)+c\\9=a+b+0\\a+b=9[/tex]             ...1

For the third point (1,9). The equation become,

[tex]f(3)=a(3)^2+b(3)+c\\21=9a+3b+0\\9a+3b=21[/tex]             ...2

On solving, first and second equation we get,

[tex]a=-1\\b=10[/tex]

Put the values of a,b, and c in a quadratic equation,

[tex]f(x)=-x^2+10x+0[/tex]

Equate the equation to zero,

[tex]-x^2+10x=0\\x(x-10)=0\\x=0, x=10[/tex]

Thus, the x-intercept represents that after 10 in. of rain there are mosquitoes, when the population of mosquitoes in a certain area as a function of inches of rainfall.

Learn more about the quadratic equation here;

https://brainly.com/question/1214333

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