P.S.—I thank Mr. C. F. Merchant for pointing out in NATURE of June 3 that the four-ordinate rule is already in use, and for giving a reference to Tchebycheff's rules, with which I was unacquainted.

Maths Integrals Formulas: The CBSE Class 12 mathematics course is heavily focused on calculus, and Chapter 7 Integrals is one of the lengthiest and most important chapters on the topic. Integrals is ...