Advanced Geometry : How to graph a quadratic function

Study concepts, example questions & explanations for Advanced Geometry

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Example Questions

Example Question #71 : Coordinate Geometry

What is the range for  below? 

Possible Answers:

Correct answer:

Explanation:

Example Question #21 : How To Graph A Quadratic Function

Find the -intercept and range for the function:

Possible Answers:

Correct answer:

Explanation:

 

Example Question #72 : Coordinate Geometry

Find the equation based on the graph shown below:

Screen shot 2015 10 21 at 3.40.06 pm

Possible Answers:

Correct answer:

Explanation:

When you look at the graph, you will see the x-intercepts are

 

and the y-intercept is 

.

These numbers are the solutions to the equation.

You can work backwards and see what the actual equation will come out as,

.

This would distribute to 

 

and then simplify to 

.

This also would show a y-intercept of .

Example Question #164 : Advanced Geometry

Possible Answers:

Correct answer:

Explanation:

Example Question #165 : Advanced Geometry

Determine the domain and range for the graph of the below function: 

Possible Answers:

Correct answer:

Explanation:

When finding the domain and range of a quadratic function, we must first find the vertex. 

Example Question #166 : Advanced Geometry

Give the -coordinate(s) of the -intercept(s) of the graph of the function

.

Possible Answers:

The graph of  has no -intercept.

Correct answer:

Explanation:

The -intercept(s) of the graph of  are the point(s) at which it intersects the -axis. The -coordinate of each is 0; their -coordinate(s) are those value(s) of  for which , so set up, and solve for , the equation:

To solve this quadratic equation, first, factor the quadratic trinomial as 

by finding two integers with sum  and product . From trial and error, we find the integers  and 2, so the equation can be rewritten as 

By the Zero Factor Principle, one of these two binomials is equal to 0, so either

,

in which case 

,

or 

,

in which case

.

The graph has two -intercepts at the points  and .

Example Question #71 : Graphing

Give the domain of the function .

Possible Answers:

The set of all real numbers 

Correct answer:

The set of all real numbers 

Explanation:

 is a polynomial function, and as such has the set of all real numbers as its domain.

Example Question #81 : Coordinate Geometry

Give the range of the function .

Possible Answers:

The set of all real numbers.

Correct answer:

Explanation:

 is a quadratic function. 

One way to find the maximum or minimum value of a quadratic function such as   is to find the vertex of its parabola; its -coordinate will be the one extremum of the range. Whether it is the minimum or maximum value depends on the quadratic coefficient; since it is a positive value here (1), it will be a minimum value.

Set  and  equal to quadratic and linear coefficients 1 and 4, respectively, and evaluating the expression :

This gives the -coordinate of the vertex; the -coordinate, and the minimum value of , can be found by evaluating , which is done by substitution:

The range is therefore .

 

 

Example Question #82 : Coordinate Geometry

Give the -coordinate of the -intercept of the graph of the function

Possible Answers:

The graph of  has no -intercept.

Correct answer:

Explanation:

The -intercept of the graph of  is the point at which it intersects the -axis. Its -coordinate is 0; its -coordinate is , which can be found by substituting 0 for  in the definition:

,

the correct choice.

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