For which of the following does f(m)−f(n)=f(m−n) for all values of m and n? Choose the correct choice from the following answers
A) f(y)=y^2	B) f(y)=y/2	C) f(y)=y+5	D) f(y)=2y−1	E) f(y)=|y|
To solve this easiest way is just put the value and see that if it equals or not.   with option 1. f(m) = m^2 and f(n) = n^2   so L.H.S = m^2 - n^2   and R.H.S = (m-n)^2 ==&gt; m^2 + n^2 -2mn.   so L.H.S not equal to R.H.S   with option 2. f(m) = m/2 and f(n) =n/2   L.H.S = m/2 - n/2 ==&gt; 1/2(m-n)   R.H.S = (m-n)/2   so L.H.S = R.H.S which is the correct answer.   f(y)=y/2
<result>B</result>
For which of the following does f(m)−f(n)=f(m−n) for all values of m and n?