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A line passes through the points, ( −2 , −15 ) and ( 2, −3 ) . Find the equation of a perpendicular line that passes through the point, ( 6 , 4 ) .

y = 1 3 x + 6

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Solving a system of linear equations using a graph

A system of linear equations includes two or more linear equations. The graphs of two lines will intersect at a single point if they are not parallel. Two parallel lines can also intersect if they are coincident, which means they are the same line and they intersect at every point. For two lines that are not parallel, the single point of intersection will satisfy both equations and therefore represent the solution to the system.

To find this point when the equations are given as functions, we can solve for an input value so that f ( x ) = g ( x ) . In other words, we can set the formulas for the lines equal to one another, and solve for the input that satisfies the equation.

Finding a point of intersection algebraically

Find the point of intersection of the lines h ( t ) = 3 t 4 and j ( t ) = 5 t .

Set h ( t ) = j ( t ) .

3 t 4 = 5 t       4 t = 9         t = 9 4

This tells us the lines intersect when the input is 9 4 .

We can then find the output value of the intersection point by evaluating either function at this input.

j ( 9 4 ) = 5 9 4          = 11 4

These lines intersect at the point ( 9 4 , 11 4 ) .

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If we were asked to find the point of intersection of two distinct parallel lines, should something in the solution process alert us to the fact that there are no solutions?

Yes. After setting the two equations equal to one another, the result would be the contradiction “0 = non-zero real number”.

Look at the graph in [link] and identify the following for the function j ( t ) :

  1. y- intercept
  2. x -intercept(s)
  3. slope
  4. Is j ( t ) parallel or perpendicular to h ( t ) (or neither)?
  5. Is j ( t ) an increasing or decreasing function (or neither)?
  6. Write a transformation description for j ( t ) from the identity toolkit function f ( x ) = x .
  1. ( 0 , 5 )
  2. ( 5 ,  0 )
  3. Slope -1
  4. Neither parallel nor perpendicular
  5. Decreasing function
  6. Given the identity function, perform a vertical flip (over the t -axis) and shift up 5 units.
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Finding a break-even point

A company sells sports helmets. The company incurs a one-time fixed cost for $250,000. Each helmet costs $120 to produce, and sells for $140.

  1. Find the cost function, C , to produce x helmets, in dollars.
  2. Find the revenue function, R , from the sales of x helmets, in dollars.
  3. Find the break-even point, the point of intersection of the two graphs C   and   R .
  1. The cost function in the sum of the fixed cost, $125,000, and the variable cost, $120 per helmet.
    C ( x ) = 120 x + 250 , 000
  2. The revenue function is the total revenue from the sale of x helmets, R ( x ) = 140 x .
  3. The break-even point is the point of intersection of the graph of the cost and revenue functions. To find the x -coordinate of the coordinate pair of the point of intersection, set the two equations equal, and solve for x .
                        C ( x ) = R ( x ) 250 , 000 + 120 x = 140 x              250 , 000 = 20 x                12 , 500 = x                          x = 12 , 500

    To find y , evaluate either the revenue or the cost function at 12,500.

    R ( 20 ) = 140 ( 12 , 500 ) = $ 1 , 750 , 000

The break-even point is ( 12,500, 1,750,000 ) .  

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Questions & Answers

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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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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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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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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
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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,
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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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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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Source:  OpenStax, Precalculus. OpenStax CNX. Jan 19, 2016 Download for free at https://legacy.cnx.org/content/col11667/1.6
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