Math Problem Statement

Use the functions f(x) = -x^2 + 4 and g(x) = 4x + 4 to answer parts (a)-(g): (a) Solve f(x) = 0. (b) Solve g(x) = 0. (c) Solve f(x) = g(x). (d) Solve f(x) > 0. (e) Solve g(x) <= 0. (f) Solve f(x) > g(x). (g) Solve f(x) >= 4.

Solution

The problem provides two functions, f(x)=x2+4f(x) = -x^2 + 4 and g(x)=4x+4g(x) = 4x + 4, and asks us to solve a series of inequalities and equations involving these functions. Let's go through each part step-by-step:

(a) Solve f(x)=0f(x) = 0

To solve f(x)=0f(x) = 0:

f(x)=x2+4=0f(x) = -x^2 + 4 = 0

x2+4=0    x2=4-x^2 + 4 = 0 \implies x^2 = 4

x=±2x = \pm 2

(b) Solve g(x)=0g(x) = 0

To solve g(x)=0g(x) = 0:

g(x)=4x+4=0g(x) = 4x + 4 = 0

4x+4=0    4x=44x + 4 = 0 \implies 4x = -4

x=1x = -1

(c) Solve f(x)=g(x)f(x) = g(x)

To solve f(x)=g(x)f(x) = g(x):

x2+4=4x+4-x^2 + 4 = 4x + 4

Simplify:

x24x=0-x^2 - 4x = 0

Factor out:

x(x+4)=0-x(x + 4) = 0

x=0 or x=4x = 0 \text{ or } x = -4

(d) Solve f(x)>0f(x) > 0

Solve x2+4>0-x^2 + 4 > 0:

x2<4    2<x<2x^2 < 4 \implies -2 < x < 2

(e) Solve g(x)0g(x) \leq 0

Solve 4x+404x + 4 \leq 0:

4x4    x14x \leq -4 \implies x \leq -1

(f) Solve f(x)>g(x)f(x) > g(x)

Solve x2+4>4x+4-x^2 + 4 > 4x + 4:

x24x<0-x^2 - 4x < 0

x(x+4)>0x(x + 4) > 0

Interval test gives:

x<4 or x>0x < -4 \text{ or } x > 0

(g) Solve f(x)4f(x) \geq 4

Solve x2+44-x^2 + 4 \geq 4:

x20x^2 \leq 0

x=0x = 0

Would you like further details or have any questions?

Related Questions:

  1. How do you solve inequalities with quadratic functions?
  2. What are the solutions to a function intersecting another line?
  3. Can x2x^2 have negative values? If not, why?
  4. How do you determine where one function is greater than another?
  5. What steps should you take when factoring polynomials?

Tip: When solving inequalities, sketching graphs can help visualize the solutions.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Linear Equations
Inequalities

Formulas

Quadratic equation formula: ax^2 + bx + c = 0
Linear equation formula: ax + b = 0

Theorems

Quadratic formula: x = (-b ± √(b^2 - 4ac)) / 2a
Inequalities rules for quadratic and linear functions

Suitable Grade Level

Grades 9-11