SOLUTION: Point P (u,v) is in the first quadrant on the graph of the line connecting the points (0,4) and (4,0). A shaded triangular region is shown in the diagram. For what point P will the

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Point P (u,v) is in the first quadrant on the graph of the line connecting the points (0,4) and (4,0). A shaded triangular region is shown in the diagram. For what point P will the      Log On


   



Question 1152314: Point P (u,v) is in the first quadrant on the graph of the line connecting the points (0,4) and (4,0). A shaded triangular region is shown in the diagram. For what point P will the area of the shaded triangular region be a maximum?
Answer by ikleyn(52779) About Me  (Show Source):
You can put this solution on YOUR website!
.

x-coordinate of the point P is "u";

y--coordinate of the point P is "v".


These coordinates satisfy equation


    u + v = 4.


The area of the triangle is 


    S = %281%2F2%29%2Au%2Av = %281%2F2%29%2Au%2A%284-u%29 = %281%2F2%29%2A%28-u%5E2+%2B+4u%29 = -%281%2F2%29%2Au%5E2+%2B+2u.


Thus the area "S" is the quadratic function of "u".


It achieves the maximum value at  u = " %28-b%29%2F%282a%29 " = -2%2F%282%2A%28-1%2F2%29%29 = %28-2%29%2F%28-1%29 = 2.


The value of the maximum is  S = %281%2F2%29%2Au%2Av%29 = %281%2F2%29%2A2%2A%284-2%29 = %281%2F2%29%2A2%2A2 = 2.


ANSWER.  The area of the triangle has the maximum at the point P = (2,2), and the value of the maximum is 2.

Solved.

------------------

If you want to expand your knowledge in this class of problem and if you want to feel a solid ground under your legs,
look into the lessons
    - HOW TO complete the square to find the minimum/maximum of a quadratic function
    - Briefly on finding the minimum/maximum of a quadratic function
    - HOW TO complete the square to find the vertex of a parabola
    - Briefly on finding the vertex of a parabola
    - A rectangle with a given perimeter which has the maximal area is a square
    - A farmer planning to fence a rectangular garden to enclose the maximal area
    - OVERVIEW of lessons on finding the maximum/minimum of a quadratic function

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic "Finding minimum/maximum of quadratic functions".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.