Math Problem Statement

Answer that question

Given the quadratic function y = x^2 - 10x + 28, construct a table of values with 5 ordered pairs, sketch the graph, and identify key characteristics of the graph such as direction, vertex, domain, range, intercepts, and axis of symmetry.

Solution

Let's work through the problem presented on the screen step by step.

The given quadratic function is:

y=x210x+28y = x^2 - 10x + 28

a. Construct a table of values with 5 ordered pairs

We can calculate the values of yy for various values of xx. Let's select x=0,2,4,6,8x = 0, 2, 4, 6, 8 for simplicity.

xxy=x210x+28y = x^2 - 10x + 28
00210(0)+28=280^2 - 10(0) + 28 = 28
22210(2)+28=42^2 - 10(2) + 28 = 4
44210(4)+28=04^2 - 10(4) + 28 = 0
66210(6)+28=46^2 - 10(6) + 28 = 4
88210(8)+28=168^2 - 10(8) + 28 = 16

Thus, the ordered pairs are:
(0,28),(2,4),(4,0),(6,4),(8,16)(0, 28), (2, 4), (4, 0), (6, 4), (8, 16)

b. Sketch the graph of the function

  • Plot the points from the table: (0,28),(2,4),(4,0),(6,4),(8,16)(0, 28), (2, 4), (4, 0), (6, 4), (8, 16).
  • Connect these points in a smooth parabolic shape.

c to i. Identify the following characteristics:

c. Direction of the Opening of the Graph

Since the coefficient of x2x^2 is positive (11), the parabola opens upward.

d. Vertex

The vertex of a parabola given by y=ax2+bx+cy = ax^2 + bx + c can be calculated using the formula:

xvertex=b2ax_{\text{vertex}} = \frac{-b}{2a}

For y=x210x+28y = x^2 - 10x + 28, a=1a = 1 and b=10b = -10:

xvertex=(10)2(1)=5x_{\text{vertex}} = \frac{-(-10)}{2(1)} = 5

Substitute x=5x = 5 back into the equation to find the yy-coordinate of the vertex:

yvertex=5210(5)+28=2550+28=3y_{\text{vertex}} = 5^2 - 10(5) + 28 = 25 - 50 + 28 = 3

So, the vertex is at (5,3)(5, 3).

e. Domain

For any quadratic function, the domain is all real numbers:

Domain: (,)\text{Domain: } (-\infty, \infty)

f. Range

Since the parabola opens upward and its minimum point is the vertex at (5,3)(5, 3), the range is:

Range: [3,)\text{Range: } [3, \infty)

g. xx-intercepts

To find the xx-intercepts, set y=0y = 0:

0=x210x+280 = x^2 - 10x + 28

Solve this quadratic equation using the quadratic formula:

x=(10)±(10)24(1)(28)2(1)x = \frac{-(-10) \pm \sqrt{(-10)^2 - 4(1)(28)}}{2(1)} x=10±1001122x = \frac{10 \pm \sqrt{100 - 112}}{2} x=10±122x = \frac{10 \pm \sqrt{-12}}{2}

Since the discriminant is negative, the function has no real xx-intercepts.

h. yy-intercept

To find the yy-intercept, set x=0x = 0:

y=0210(0)+28=28y = 0^2 - 10(0) + 28 = 28

So, the yy-intercept is at (0,28)(0, 28).

i. Axis of Symmetry

The axis of symmetry is the vertical line that passes through the vertex. Since the vertex is at x=5x = 5, the equation of the axis of symmetry is:

x=5x = 5


Would you like more details on any of these steps?

Related Questions:

  1. How would you solve a quadratic equation with real xx-intercepts?
  2. How can you determine the vertex of a quadratic function from its standard form?
  3. What are the differences between the domain and range of a quadratic function?
  4. How do you solve for the xx-intercepts using the quadratic formula?
  5. What is the significance of the axis of symmetry in a parabola?

Tip:

To quickly find the direction of a parabola, look at the sign of the coefficient of x2x^2: positive means it opens upward, negative means it opens downward.

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Math Problem Analysis

Mathematical Concepts

Quadratic Functions
Graphing
Parabolas

Formulas

y = ax^2 + bx + c
x_vertex = -b/(2a)
Quadratic formula: x = (-b ± sqrt(b^2 - 4ac)) / (2a)

Theorems

Properties of Parabolas
Vertex Formula
Axis of Symmetry

Suitable Grade Level

Grade 9-10