The area of mathematics generally taken to include those topics that involve the use of limiting processes. Thus differential calculus and integral calculus certainly come under this heading. Besides these, there are other topics, such as the summation of infinite series, which involve ‘infinite’ processes of this sort. The Binomial Theorem, a theorem of algebra, leads on into analysis when the index is no longer a positive integer, and the study of sine and cosine, which begins as trigonometry, becomes analysis when the power series for the functions are derived. The term ‘analysis’ has also come to be used to indicate a rather more rigorous approach to the topics of calculus, and to the foundations of the real number system.