1. f(x) = -2*x^(-1) + 1/8 *x +1,4.
f'(x) = -2*(-1)*x^(-2) +1/8*1 = 2/(x²) + 1/8.
f'(-4) = 2/16 +1/8 = 2/8 = 1/4.
2.f(x) = 1/x = x^(-1)
f'(x) = -1*x^(-2) = -1/x².
f'(-2) = -1/(-2)² = -1/4.
3.f(x) = (3x+1)² -3
f'(x) = 2(3x+1)^1*(3x+1)' = 2*{3x+1)*3 = 6(3x+1).
f'(2/3) = 6*(3*(2/3)+1) = 18.