Math Problem Statement

The function f(x) is defined by f(x) = ax^2 + bx + c, where a, b, and c are constants. The graph of y = f(x) in the xy-plane passes through the points (7, 0) and (-3, 0). If a is an integer greater than 1, which of the following could be the value of a + b?

Solution

The problem in the image is asking about a quadratic function f(x)=ax2+bx+cf(x) = ax^2 + bx + c where aa, bb, and cc are constants. The graph passes through the points (7,0)(7, 0) and (3,0)(-3, 0). We are tasked with finding the value of a+ba + b, given that aa is an integer greater than 1.

Steps:

  1. Roots of the Quadratic: Since (7,0)(7, 0) and (3,0)(-3, 0) are points on the graph, they are the roots of the quadratic equation. Therefore, the quadratic can be written in factored form: f(x)=a(x7)(x+3)f(x) = a(x - 7)(x + 3) Expanding this expression gives: f(x)=a(x2+3x7x21)=a(x24x21)f(x) = a(x^2 + 3x - 7x - 21) = a(x^2 - 4x - 21) So, the quadratic function becomes: f(x)=ax24ax21af(x) = ax^2 - 4ax - 21a

  2. Identifying aa and bb: From this expanded form, we can identify that:

    • b=4ab = -4a
    • We are asked to find a+ba + b, which is: a+b=a4a=3aa + b = a - 4a = -3a
  3. Finding a+ba + b: Since aa is an integer greater than 1, the smallest possible value of aa is 2. Let's calculate a+ba + b for a=2a = 2: a+b=3a=3(2)=6a + b = -3a = -3(2) = -6

Thus, the value of a+ba + b is 6\boxed{-6}.

Would you like more details or have any further questions?

Here are 5 related questions to consider:

  1. How do you factor a quadratic equation given its roots?
  2. What are other methods to find the vertex of a quadratic function?
  3. How does the discriminant of a quadratic equation relate to its graph?
  4. Can the quadratic function have more than two real roots?
  5. How does the value of aa in ax2+bx+cax^2 + bx + c affect the shape of the parabola?

Tip: When dealing with quadratic functions, factoring is often the easiest method to identify roots and rewrite the equation in standard form.

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Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Factoring
Roots of Quadratic Equations

Formulas

f(x) = ax^2 + bx + c
Factored form of a quadratic function based on roots
Expanded form of f(x)

Theorems

Root Theorem for Quadratic Functions
Factoring Quadratics

Suitable Grade Level

Grade 10-12