Math Problem Statement

The points (1, 7), (2, 10), and (3, 11) lie on a model of the form y = ax^2 + bx + c. a) Construct three equations in terms of a, b, and c. b) Use technology to find a, b, and c. c) Hence determine the model.

Solution

To solve the problem, we will follow the steps outlined:

Given:

We have three points (1,7)(1, 7), (2,10)(2, 10), and (3,11)(3, 11) that lie on a quadratic model of the form y=ax2+bx+cy = ax^2 + bx + c.

(a) Construct three equations in terms of aa, bb, and cc.

Substitute each point into the equation y=ax2+bx+cy = ax^2 + bx + c:

  1. For the point (1,7)(1, 7): 7=a(1)2+b(1)+c    a+b+c=77 = a(1)^2 + b(1) + c \implies a + b + c = 7

  2. For the point (2,10)(2, 10): 10=a(2)2+b(2)+c    4a+2b+c=1010 = a(2)^2 + b(2) + c \implies 4a + 2b + c = 10

  3. For the point (3,11)(3, 11): 11=a(3)2+b(3)+c    9a+3b+c=1111 = a(3)^2 + b(3) + c \implies 9a + 3b + c = 11

(b) Use technology to find aa, bb, and cc.

We have the following system of equations:

1. & \quad a + b + c = 7 \\ 2. & \quad 4a + 2b + c = 10 \\ 3. & \quad 9a + 3b + c = 11 \end{aligned}$$ To solve this, we can use substitution, elimination, or a matrix method. Let's solve it using a matrix approach: $$\begin{bmatrix} 1 & 1 & 1 \\ 4 & 2 & 1 \\ 9 & 3 & 1 \end{bmatrix} \begin{bmatrix} a \\ b \\ c \end{bmatrix} = \begin{bmatrix} 7 \\ 10 \\ 11 \end{bmatrix}$$ I'll solve this system now.### (b) Solution for $$a$$, $$b$$, and $$c$$: The solutions are: $$a = -1, \quad b = 6, \quad c = 2$$ ### (c) Determine the model. Substitute the values of $$a$$, $$b$$, and $$c$$ into the quadratic equation $$y = ax^2 + bx + c$$: $$y = -x^2 + 6x + 2$$ This is the quadratic model that fits the given points. Would you like a detailed explanation of any part of this solution? Here are some related questions you might consider: 1. How can you verify that the points lie on the derived model? 2. What is the vertex of the quadratic model $$y = -x^2 + 6x + 2$$? 3. How does the model change if an additional point is given? 4. What is the axis of symmetry for this quadratic function? 5. Can this quadratic function have a maximum or minimum, and where does it occur? **Tip:** When solving systems of equations, using matrices can simplify the process, especially for larger systems.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Systems of Equations

Formulas

Quadratic equation: y = ax^2 + bx + c
Linear system solution methods: substitution, elimination, matrix methods

Theorems

Solving systems of equations
Properties of quadratic functions

Suitable Grade Level

Grades 9-12