If the function y = f (x) satisfies f (a + b) = f (a) + F (b) for all real numbers a and B, and f (1) = 8, then f (- 1 / 2)=_________

If the function y = f (x) satisfies f (a + b) = f (a) + F (b) for all real numbers a and B, and f (1) = 8, then f (- 1 / 2)=_________

f(1/2)+f(1/2)=f(1)=8
f(1/2)=f(1)/2=4
f(0)+f(0)=f(0)
f(0)=0
f(-1/2)+f(1/2)=f(0)=0
f(-1/2)=-f(1/2)=-4