Key Ideas
1Power Rule. d/dx[x^n] = n*x^(n-1).
2Constant Multiple Rule. d/dx[c*f(x)] = c*f'(x) — constants pass through the derivative unchanged.
3Sum/Difference Rule. d/dx[f(x) +/- g(x)] = f'(x) +/- g'(x) — differentiate term by term.
4Product Rule. d/dx[f(x)*g(x)] = f'(x)*g(x) + f(x)*g'(x).
5Quotient Rule. d/dx[f(x)/g(x)] = [f'(x)*g(x) - f(x)*g'(x)] / [g(x)]^2.