What is the derivative of f(x)=x3+2x2−x+4f(x) = x^3 + 2x^2 - x + 4f(x)=x3+2x2−x+4?
3x2+4x−13x^2 + 4x - 13x2+4x−1
3x2+2x−13x^2 + 2x - 13x2+2x−1
x2+4x−1x^2 + 4x - 1x2+4x−1
3x2+4x+43x^2 + 4x + 43x2+4x+4