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