The variables x and y have a quadratic relationship. Tripling the value of x causes the value of y to increase by a factor of nine. When x has a value of 3, y has a value of 2. What will be the value of y when x has a value of 9?​

Respuesta :

Answer:

The value of y when x has a value of 9 is 18

Step-by-step explanation:

Functions

The variables x and y are said to have a quadratic relationship. That information is not enough to set up a general equation for both variables.

Furthermore, we know that tripling the value of x causes the value of y to be multiplied by 9. That leads us to establish a proportional equation between them, as follows:

[tex]y=kx^2[/tex]

Where k is an unknown constant.

Let's use the given point (3,2) to find the value of k:

[tex]2=k(3)^2[/tex]

[tex]2=9k[/tex]

Solving for k:

[tex]\displaystyle k=\frac{2}{9}[/tex]

The equation is now:

[tex]\displaystyle y=\frac{2}{9}x^2[/tex]

Now find y when x=9:

[tex]\displaystyle y=\frac{2}{9}(9)^2[/tex]

[tex]\displaystyle y=\frac{2}{9}\cdot 81=18[/tex]

The value of y when x has a value of 9 is 18