7   Definite Integral
In the previous sections, we have studied about the indefinite integrals and discussed
few methods of finding them including integrals of some special functions In this
section, we shall study what is called definite integral of a function The definite integral
has a unique value A definite integral is denoted by 
( )
b
∫a f x dx
, where a is called the
lower limit of the integral and b is called the upper limit of the integral