Function Problem: Area of Rectangle with 100ft Perimeter

  • Thread starter Thread starter Arreat
  • Start date Start date
  • Tags Tags
    Function
Click For Summary
SUMMARY

The area of a rectangle with a perimeter of 100 feet can be expressed as a function of its length, L. The correct formulation is A(L) = L(50 - L), which simplifies to A = -L^2 + 50L. The perimeter equation 100 = 2L + 2W leads to W = 50 - L, allowing for the substitution into the area formula. This establishes the relationship between length and area definitively.

PREREQUISITES
  • Understanding of basic algebraic equations
  • Knowledge of perimeter and area formulas for rectangles
  • Ability to manipulate equations and substitute variables
  • Familiarity with quadratic functions
NEXT STEPS
  • Study the properties of quadratic functions and their graphs
  • Learn how to derive functions from geometric constraints
  • Explore optimization techniques in calculus for maximizing area
  • Investigate real-world applications of perimeter and area calculations
USEFUL FOR

Students in mathematics, educators teaching geometry, and anyone interested in algebraic functions and their applications in geometry.

Arreat
Messages
1
Reaction score
0

Homework Statement



Express the area of a rectangle with the perimeter of 100 feet as a function of the lengh L of one of its sides


Homework Equations


100=2w+2l


The Attempt at a Solution


As far as I can get is,

L = 50 -2w

Just writing the function is a problem, I assume it's something like but I'm not sure, sorry if I'm completely off it's been a long day.
A(W) = (50-2w)(w) = 50w - 2w^2
or
A = w(50-w)
 
Physics news on Phys.org
You successfully wrote the function for area (in two equivalent forms).
 
If [tex]100=2L+2W[/tex]

then [tex]L=50-W[/tex] but [tex]L\neq 50-2W[/tex]

Therefore your 2nd equation for the function is the correct one. [tex]A=-W^2+50W[/tex]

But the question asked as a function of the length, not width. It will be similar though. Just make width the subject of the perimeter equation and substitute into the area formula.
 
Last edited:

Similar threads

  • · Replies 8 ·
Replies
8
Views
3K
Replies
14
Views
2K
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
12K
  • · Replies 21 ·
Replies
21
Views
4K
Replies
18
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 29 ·
Replies
29
Views
4K
  • · Replies 19 ·
Replies
19
Views
8K
Replies
15
Views
4K