Which of the following is the derivative with respect to x of (x + 1)^3 - x^3? Date of Exam November 1994 Subject Mathematics, Surveying and Transportation Engineering Problem Which of the following is the derivative with respect to x of $(x + 1)^3 - x^3$? A. 6x + 3 C. 1 + 2x - 3x^{2} B. 3x^{2} + 2x + 1 D. 6x - 3 Answer Key Click here to show or hide the answer key [ A ] Solution Click here to expand or collapse this section $\begin{align} \dfrac{d}{dx} \Big[ (x + 1)^3 - x^3 \Big] & = 3(x + 1)^2 - 3x^2 \\ & = 3(x^2 + 2x + 1) - 3x^2 \\ & = 3x^2 + 6x + 3 - 3x^2 \\ & = 6x + 3 ~ \leftarrow ~ \text{answer} \end{align}$ Category Differential Calculus Differentiation First Derivative Log in or register to post comments