Product Rule - A Common Error

A Common Error

It is a common error, when studying calculus, to suppose that the derivative of (uv) equals (u ′)(v ′). Leibniz himself made this error initially; however, there are clear counterexamples. Consider a differentiable function ƒ(x) whose derivative is ƒ '(x). This function can also be written as ƒ(x) · 1, since 1 is the identity element for multiplication. If the above-mentioned misconception were true, (u′)(v′) would equal zero. This is true because the derivative of a constant (such as 1) is zero and the product of ƒ '(x) · 0 is also zero.

Read more about this topic:  Product Rule

Famous quotes containing the words common and/or error:

    Human life in common is only made possible when a majority comes together which is stronger than any separate individual and which remains united against all separate individuals. The power of this community is then set up as “right” in opposition to the power of the individual, which is condemned as “brute force.”
    Sigmund Freud (1856–1939)

    If the individual, or heretic, gets hold of some essential truth, or sees some error in the system being practised, he commits so many marginal errors himself that he is worn out before he can establish his point.
    Ezra Pound (1885–1972)