Machine-translated by Google. Questions are authored in English.
Top

Discussion

In the Taylor expansion of \( f \) about \( x = a \), the coefficient of \( (x-a)^{n} \) is

  • A.\( n!\,f^{(n)}(a) \)
  • B.\( f^{(n)}(a)/n \)
  • C.\( f^{(n)}(a)/n! \)
  • D.\( f^{(n)}(a) \)

Answer: C

Writing \( f(x) = \sum c_{n}(x-a)^{n} \) and differentiating \( n \) times at \( x = a \) leaves only the \( n \)th term, giving \( f^{(n)}(a) = n!\,c_{n} \) and so

\[ c_{n} \;=\; \frac{f^{(n)}(a)}{n!}. \]

The factorial divisor is what makes the series converge for well-behaved functions; omitting it produces a series that diverges for all but the smallest arguments

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.