March 7, 2011

MEANING OF THE SYMBOLS d AND ∫

Posted in CHAPTER 1 at 4:38 pm by Anu

To learn how to calculate, we have to look into the meaning of two principal symbols that are used in calculus. Symbols are :

1)      “d” which merely means “a little bit of”. Thus dx means a little bit of x ; or du means a little bit of ‘u’. it can also be called as “an element of x”; or “element of u”. thus little bits(elements) are considered to be indefinitely small.

2)      ∫ nothing but a long S or “the sum of”. Thus ∫dx means the sum of all little bits of x; ∫du means the sum of all little bits of u. it can also be called as “integral of x”. if x is considered to be made of lot of little bits,each of which is called dx,if you add them all together you get the sum of all dx’s(which is same thing as the whole of x). so the word “integral” means “the whole”.