Math Problem Statement

Given f(x) = -4x^2 + 8x + 11, find f(-3)

Solution

To solve the problem, we need to evaluate the function f(x)=4x2+8x+11f(x) = -4x^2 + 8x + 11 at x=3x = -3.

Let's substitute x=3x = -3 into the function:

f(3)=4(3)2+8(3)+11f(-3) = -4(-3)^2 + 8(-3) + 11

Now, calculate each term:

  1. (3)2=9(-3)^2 = 9, so 4(3)2=4×9=36-4(-3)^2 = -4 \times 9 = -36
  2. 8(3)=248(-3) = -24
  3. The constant term is 1111

Substitute these values back into the function:

f(3)=3624+11f(-3) = -36 - 24 + 11

Simplify the expression:

f(3)=60+11=49f(-3) = -60 + 11 = -49

So, the value of f(3)f(-3) is -49.

Would you like more details or have any questions?

Here are some related questions that might interest you:

  1. How do you evaluate a function at a different value?
  2. What is the significance of finding the value of a function at a specific point?
  3. How do you graph a quadratic function like f(x)=4x2+8x+11f(x) = -4x^2 + 8x + 11?
  4. What does the negative coefficient of x2x^2 tell you about the parabola?
  5. How do you find the vertex of the quadratic function?

Tip: Remember that substituting values carefully and following the order of operations (PEMDAS) will help avoid mistakes when evaluating functions.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Function Evaluation

Formulas

f(x) = ax^2 + bx + c
f(x) = -4x^2 + 8x + 11

Theorems

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Suitable Grade Level

Grades 9-10