Math Problem Statement

solve quadratic inequality y < x² + 2x - 4

Solution

To solve the quadratic inequality y<x2+2x4y < x^2 + 2x - 4, we follow these steps:

Step 1: Understand the inequality

The given inequality is y<x2+2x4y < x^2 + 2x - 4, which describes the region below the parabola defined by y=x2+2x4y = x^2 + 2x - 4.

Step 2: Analyze the quadratic expression

The quadratic expression x2+2x4x^2 + 2x - 4 represents a parabola that opens upwards since the coefficient of x2x^2 is positive. The vertex of this parabola occurs at the point where the derivative 2x+2=02x + 2 = 0, giving x=1x = -1.

Substitute x=1x = -1 into the equation to find the vertex: y=(1)2+2(1)4=124=5y = (-1)^2 + 2(-1) - 4 = 1 - 2 - 4 = -5 So, the vertex of the parabola is at (1,5)(-1, -5).

Step 3: Graph the inequality

  • The equation y=x2+2x4y = x^2 + 2x - 4 represents a parabola with its vertex at (1,5)(-1, -5), and it opens upward.
  • The inequality y<x2+2x4y < x^2 + 2x - 4 represents all the points below this parabola.

Step 4: Interpret the solution

  • In terms of xx, there is no specific range for xx values where the inequality holds. The solution is a region in the xyxy-plane where the yy-values are less than the yy-values on the parabola.

Final Answer:

The solution to the inequality y<x2+2x4y < x^2 + 2x - 4 is the set of all points (x,y)(x, y) in the plane where the yy-coordinate is less than the value of x2+2x4x^2 + 2x - 4 for a given xx-coordinate.

Would you like more details or have any questions?


Here are 5 related questions to expand on this topic:

  1. How do you solve quadratic inequalities in one variable?
  2. What is the significance of the vertex in a parabola?
  3. How do we determine the direction of a parabola's opening?
  4. How do you graph quadratic inequalities?
  5. What is the difference between solving quadratic inequalities and equations?

Tip: Always remember that the solution to a quadratic inequality involves regions in the coordinate plane, not just specific points!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Inequalities
Graphing Parabolas

Formulas

Quadratic expression: ax² + bx + c
Vertex formula: x = -b/2a

Theorems

Properties of Parabolas
Inequalities in two variables

Suitable Grade Level

Grades 9-11