Derivative

Solve d/dx (x^3 - 4x)

Working

1. 1

   Identify the function

   You are differentiating f(x) = x^3 - 4x.

2. 2

   Apply the power rule

   Differentiate each term separately and add: d/dx (1x^3) = 1·3x^2, and d/dx (-4x^1) = -4·1x^0.

3. 3

   Read off the derivative

   So the derivative is 3x^2 - 4.

Equations

Worked through by GraphingCalc TI-84. The step solver handles quadratics, linear equations, inequalities, factoring, systems of two equations, standard derivatives and numeric evaluation — for anything more elaborate, use the graphing calculator to explore the function directly.