Define a function k that determines the length of the fence in feet in terms of the fence's width in feet, w , given the total amount of fence is 1000 feet.

Question

k(w)=500-L came up with this

i know that 1000=2l+2w  keeps saying its wrong

 

Answer 1

Let's start with what you know  (1000=2l+2w) and create a "bridge" to what you don't know (hey! that sounds like one of The Seven Laws of Teaching by John Milton Gregory).

 

Your expression has two variables: L and W      (I'll use capital letters for clarity)

The problem asks for a function of W and the total amount of fence.  Thus, W is an independent variable (we often plot those on the x-axis).

The problem calls the function k and it determines the value of the dependent variable L, given a value of the independent variable W.

   k(w) is what we name the function

  L = k(W) = (1000 - 2W)/2  = 500 - W

        k(W) = 500 - W          (so, given a W, we can find the corresponding L)

 

Now (very important):  Most of us learn far more from our mistakes that we like to admit; we are taught that getting a high score is more important than learning.  Well, it isn't!  The act of learning and the process of learning how to learn will stick with you for years after you have forgotten this problem, these Answers, your book/teacher/school, etc.  Therefore, get enough information so that you won't make a similar error in the future.

Answer 2

2L + 2w = 1000

 

L + w = 500

 

So, L = 500 - w

 

k(w) = length of fence in terms of w  

 

k(w) = 500 -w

 

Note:  k is a function of w, your answer, k(w) = 500 - L,  is not a function of w.