If, by a wrong calculation (method, algorithm, operation, etc.) in mathematics, physics, chemistry, and in general in any field of knowledge, one arrives to the right answer, this is called a Lucky Calculation (Method, Algorithm, Operation, etc.)! The wrong calculation (method, algorithm, operation, etc.) should be funny (somehow similarly to a correct one, but producing confusion and liking it)!
Can someone find such Lucky Integration or Differentiation?
 Smarandache, Florentin, "Collected Papers", Vol. II, University
of Kishinev Press, Kishinev, p. 200, 1997.
 Ashbacher, Charles, "Smarandache Lucky Math", in <Smarandache Notions Journal>, Vol. 9, p. 155, 1998.