If a function f is defined by f(x)= -1/x for all non zero numbers x. If f(a) = -1/2 and f(ab) = 1/8 then b= ?  Choose the correct choice from the following options
A) -1/4
B) 1/4
C) 4
D) -4
E) 12
f(a) = -1/2 = -1/a, and thus a = 2   f(ab) = 1/8, and thus ab = -8   2b = -8   b = -4   The answer is -4.
<result>D</result>
If a function f is defined by f(x)= -1/x for all non zero numbers x. If f(a) = -1/2 and f(ab) = 1/8 then b= ?