Use the table to answer the question.

This table shows the corresponding y-values for a given set of x-values.
x-values y-values
−1
6
0 5
1 6
2 9
3 14
Create a quadratic model for the dataset in the xy
-chart.

(1 point)
Responses

f(x)=x2+5
f left parenthesis x right parenthesis equals x squared plus 5

f(x)=x+5
f left parenthesis x right parenthesis equals x plus 5

f(x)=2x+5
f left parenthesis x right parenthesis equals 2 x plus 5

f(x)=x2+7

1 answer

To create a quadratic model for the given dataset in the xy-chart, we can use the data points provided and identify a quadratic function of the form \( f(x) = ax^2 + bx + c \).

Based on the data:

  • At \( x = 0 \), \( y = 5 \)
  • At \( x = 1 \), \( y = 6 \)
  • At \( x = 2 \), \( y = 9 \)
  • At \( x = 3 \), \( y = 14 \)

We can see that the y-values are not consistent with a linear function and suggest a quadratic relation.

To find a quadratic function, we can use the points to set up a system of equations. Let's take three points and plug them into the general form:

  1. For \( x = 0 \), \( f(0) = c = 5 \)
  2. For \( x = 1 \), \( f(1) = a(1)^2 + b(1) + c = 6 \)
  3. For \( x = 2 \), \( f(2) = a(2^2) + b(2) + c = 9 \)

This leads to the following equations:

  1. \( c = 5 \)
  2. \( a + b + 5 = 6 \) → \( a + b = 1 \) (Equation 1)
  3. \( 4a + 2b + 5 = 9 \) → \( 4a + 2b = 4 \) → \( 2a + b = 2 \) (Equation 2)

Now we have two equations:

  • Equation 1: \( a + b = 1 \)
  • Equation 2: \( 2a + b = 2 \)

We can solve these equations. First, subtract Equation 1 from Equation 2:

\[ (2a + b) - (a + b) = 2 - 1 \ 2a - a = 1 \ a = 1 \]

Now that we have \( a \), we can find \( b \):

Using Equation 1: \[ 1 + b = 1 \ b = 0 \]

Thus, we have \( a = 1 \), \( b = 0 \), and \( c = 5 \). The quadratic model is:

\[ f(x) = 1x^2 + 0x + 5 \ f(x) = x^2 + 5 \]

So, the final answer is:

\( f(x) = x^2 + 5 \)

This matches one of the options given:

f(x) = x² + 5