Math Problem Statement

Find the solution of the equation x2 -2x -3 = 0 by graphing.

Solution

To solve the equation x22x3=0x^2 - 2x - 3 = 0 by graphing, we need to follow these steps:

  1. Rewrite the equation as a function:
    y=x22x3y = x^2 - 2x - 3

  2. Graph the function:
    Plot the parabola described by the equation y=x22x3y = x^2 - 2x - 3 on the coordinate plane.

  3. Identify the x-intercepts:
    The solutions to the equation x22x3=0x^2 - 2x - 3 = 0 are the x-values where the graph intersects the x-axis (i.e., where y=0y = 0).

Steps:

  • Step 1: Identify key points like the vertex and the axis of symmetry.
    The axis of symmetry is given by x=b2ax = -\frac{b}{2a}. Here, a=1a = 1 and b=2b = -2, so: x=(2)2(1)=1x = \frac{-(-2)}{2(1)} = 1 The vertex lies on this line.

  • Step 2: Compute the vertex by substituting x=1x = 1 into the equation: y=(1)22(1)3=123=4y = (1)^2 - 2(1) - 3 = 1 - 2 - 3 = -4 The vertex is at (1,4)(1, -4).

  • Step 3: Plot additional points to create the shape of the parabola.

  • Step 4: Draw the graph and identify where it intersects the x-axis.

When you graph the parabola, you will see that it intersects the x-axis at two points, which are the solutions to the equation.

Graph:

The graph of y=x22x3y = x^2 - 2x - 3 will intersect the x-axis at x=1x = -1 and x=3x = 3.

Solution:

The solutions to the equation x22x3=0x^2 - 2x - 3 = 0 are x=1x = -1 and x=3x = 3.

Would you like more details or have any questions?


Related Questions:

  1. How do you find the vertex of a parabola from its equation?
  2. How do you solve quadratic equations using the quadratic formula?
  3. What is the significance of the discriminant in a quadratic equation?
  4. How do you determine the direction of a parabola (whether it opens upwards or downwards)?
  5. How do you factor quadratic equations to find their roots?

Tip: When graphing a quadratic equation, always start by finding the vertex and axis of symmetry to make plotting easier.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Graphing Parabolas

Formulas

Quadratic equation formula: ax^2 + bx + c = 0
Axis of symmetry formula: x = -b/(2a)

Theorems

Quadratic formula
Properties of parabolas

Suitable Grade Level

Grades 8-10