Question

Anne has a broken ruler. It starts at the 3-inch mark and ends at the 12-inch mark. Explain how Anne could use the ruler to measure the length of a line segment in inches.

Answer 1

The perceived length subtracted by three would give the measure of the length of a line segment. 

x = perceived length
f(x) = actual length

Using this "broken ruler" you would need to use this simple function to get that actual length: 

f(x)= x-3

Answer 2

Answer:

$f(x) = x - 3$, where f(x) is the actual length and x is the measured length.  

Step-by-step explanation:

We are given following insight in the question:

The reading of the ruler starts from 3 inch and goes up-to 12 inch.

So, since the measure starts from 3 inch, whatever she measures will have an extra 3 units added to the measure.

For example if she measured an object to be 4 inch it is actually 1 inch long. This is due to the extra 3 inch measure added.

This whole situation can be explain with the help of a function.

Let f(x) be the actual length of the object and x be the scale measure of the object which consist 3 inch extra.

So, the actual length can be given by a function,

$f(x) = x - 3$

So, if she measures an an object to be 7, then x = 7 and actual length f(x) = 7 - 3 = 4 inch.