An expression is shown below: f(x) = 2x2 − 5x + 3 Part A: What are the x-intercepts of the graph of f(x)? Show your work. (2 points) Part B: Is the vertex of the graph of f(x) going to be a maximum or minimum? What are the coordinates of the vertex? Justify your answers and show your work. (3 points) Part C: What are the steps you would use to graph f(x)? Justify that you can use the answers obtained in Part A and Part B to draw the graph. (5 points)

Respuesta :

Answer:

Step-by-step explanation:

A. f(x) = (2x-3)(x-1)

B. since the coefficient of x^2 is positive, the parabola opens upward.

C. plot the vetex, which is between the roots, at x = 5/4, plot the zeroes

plot the points at x=1,2, draw a curve through them.

You can use any of several handy online graphing tools to verify your work.

Solving the quadratic equation, and finding it's vertex, it is found that:

  • a) The x-intercepts are [tex]x = \frac{3}{2}[/tex] and [tex]x = 1[/tex].
  • b) Since the coefficient a is positive, it is a minimum. The coordinates of the vertex are [tex](\frac{5}{4}, -\frac{1}{8})[/tex]
  • c) Using the x-intercepts, the vertex and the y-intercept, the graph is given at the end of this answer.

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Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

[tex]ax^{2} + bx + c, a\neq0[/tex].

This polynomial has roots, also called x-intercepts, [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:

[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]

[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]

[tex]\Delta = b^{2} - 4ac[/tex]

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Vertex of a quadratic function:

Suppose we have a quadratic function in the following format:

[tex]f(x) = ax^{2} + bx + c[/tex]

It's vertex is the point [tex](x_{v}, y_{v})[/tex]

In which

[tex]x_{v} = -\frac{b}{2a}[/tex]

[tex]y_{v} = -\frac{\Delta}{4a}[/tex]

Where

[tex]\Delta = b^2-4ac[/tex]

If a<0, the vertex is a maximum point, that is, the maximum value happens at [tex]x_{v}[/tex], and it's value is [tex]y_{v}[/tex].

If a>0, the vertex is a minimum point, that is, the minimum value happens at [tex]x_{v}[/tex], and it's value is [tex]y_{v}[/tex].

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Question a:

We have the following quadratic equation:

[tex]f(x) = 2x^2 - 5x + 3[/tex]

Which has [tex]a = 2, b = -5, c = 3[/tex]

The x-intercepts are the roots, so:

[tex]\Delta = (-5)^2 - 4(2)(3) = 1[/tex]

[tex]x_{1} = \frac{-(-5) + \sqrt{1}}{2(2)} = \frac{3}{2}[/tex]

[tex]x_{2} = \frac{-(-5) - \sqrt{1}}{2(2)} = 1[/tex]

The x-intercepts are [tex]x = \frac{3}{2}[/tex] and [tex]x = 1[/tex].

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Question b:

Since the coefficient a is positive, it is a minimum.

To find the coordinates, we apply the formula. Thus:

[tex]x_{v} = -\frac{(-5)}{2(2)} = \frac{5}{4}[/tex]

[tex]y_{v} = -\frac{1}{4(2)} = -\frac{1}{8}[/tex]

The coordinates of the vertex are [tex](\frac{5}{4}, -\frac{1}{8})[/tex]

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Question c:

  • The x-intercepts are [tex]x = \frac{3}{2}[/tex] and [tex]x = 1[/tex].
  • The coordinates of the vertex are [tex](\frac{5}{4}, -\frac{1}{8})[/tex]
  • The y-intercept is at [tex]y = f(0) = 3[/tex].

Using this, we get the graph given at the end of this answer.  

A similar question is given at https://brainly.com/question/22851074

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