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Describing sets on the real-number line

Describe the intervals of values shown in [link] using inequality notation, set-builder notation, and interval notation.

Line graph of 1<=x<=3 and 5<x.

To describe the values, x , included in the intervals shown, we would say, “ x is a real number greater than or equal to 1 and less than or equal to 3, or a real number greater than 5.”

Inequality 1 x 3 or x > 5
Set-builder notation { x | 1 x 3 or x > 5 }
Interval notation [ 1 , 3 ] ( 5 , )

Remember that, when writing or reading interval notation, using a square bracket means the boundary is included in the set. Using a parenthesis means the boundary is not included in the set.

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Given [link] , specify the graphed set in

  1. words
  2. set-builder notation
  3. interval notation
Line graph of -2<=x, -1<=x<3.

  1. values that are less than or equal to –2, or values that are greater than or equal to –1 and less than 3;
  2. { x | x 2 or 1 x < 3 } ;
  3. ( , 2 ] [ 1 , 3 )

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Finding domain and range from graphs

Another way to identify the domain and range of functions is by using graphs. Because the domain refers to the set of possible input values, the domain of a graph consists of all the input values shown on the x -axis. The range is the set of possible output values, which are shown on the y -axis. Keep in mind that if the graph continues beyond the portion of the graph we can see, the domain and range may be greater than the visible values. See [link] .

Graph of a polynomial that shows the x-axis is the domain and the y-axis is the range

We can observe that the graph extends horizontally from −5 to the right without bound, so the domain is [ −5 , ) . The vertical extent of the graph is all range values 5 and below, so the range is ( −∞ , 5 ] . Note that the domain and range are always written from smaller to larger values, or from left to right for domain, and from the bottom of the graph to the top of the graph for range.

Finding domain and range from a graph

Find the domain and range of the function f whose graph is shown in [link] .

Graph of a function from (-3, 1].

We can observe that the horizontal extent of the graph is –3 to 1, so the domain of f is ( 3 , 1 ] .

The vertical extent of the graph is 0 to –4, so the range is [ 4 , 0 ) . See [link] .

Graph of the previous function shows the domain and range.
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Finding domain and range from a graph of oil production

Find the domain and range of the function f whose graph is shown in [link] .

Graph of the Alaska Crude Oil Production where the y-axis is thousand barrels per day and the -axis is the years.
(credit: modification of work by the U.S. Energy Information Administration) http://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=MCRFPAK2&f=A.

The input quantity along the horizontal axis is “years,” which we represent with the variable t for time. The output quantity is “thousands of barrels of oil per day,” which we represent with the variable b for barrels. The graph may continue to the left and right beyond what is viewed, but based on the portion of the graph that is visible, we can determine the domain as 1973 t 2008 and the range as approximately 180 b 2010.

In interval notation, the domain is [1973, 2008], and the range is about [180, 2010]. For the domain and the range, we approximate the smallest and largest values since they do not fall exactly on the grid lines.

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Given [link] , identify the domain and range using interval notation.

Graph of World Population Increase where the y-axis represents millions of people and the x-axis represents the year.

domain =[1950,2002] range = [47,000,000,89,000,000]

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Questions & Answers

differentiate between demand and supply giving examples
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In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
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other things being equal
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When MP₁ becomes negative, TP start to decline. Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
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Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
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What is different between quantity demand and demand?
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Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
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Economic growth as an increase in the production and consumption of goods and services within an economy.but Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
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it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
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In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50. A,Calculate quantities of x and y which maximize utility. B,Calculate value of Lagrange multiplier. C,Calculate quantities of X and Y consumed with a given price. D,alculate optimum level of output .
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Answer
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the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
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suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
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types of unemployment
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What is the difference between perfect competition and monopolistic competition?
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Source:  OpenStax, Algebra and trigonometry. OpenStax CNX. Nov 14, 2016 Download for free at https://legacy.cnx.org/content/col11758/1.6
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