1) f(0) = 1+0/1-0 = 1/1 = 1
2) f(2) = 1+2/1-2 = 3/-1 = -3
3) f(-2) = 1+(-2)/1-(-2) = -1/3
4) f(a) = 1+a/1-a
5) f(1/a) = 1+1/a/1-1/a = 1+1/a / a-1/a = (1+a)/a = 1+(1/a)
1) f(0) = 1+0/1-0 = 1/1 = 1
2) f(2) = 1+2/1-2 = 3/-1 = -3
3) f(-2) = 1+(-2)/1-(-2) = -1/3
4) f(a) = 1+a/1-a
5) f(1/a) = 1+1/a/1-1/a = 1+1/a / a-1/a = (1+a)/a = 1+(1/a)