First of all sorry for asking such a dumb question
What is an indefinite integral?
Is it the difference between y=f(a) from f(b)=0? I mean, if f(b)=0 and we are to determine the integral at x=a of f(x) does that mean indefinite integral for this condition is int of f(x) from b to a?
The indefinite integral of $f(x)$ is the integral without upper and lower bounds, and is defined to be the antiderivative of $f(x)$ so is equal to the general function whose derivative is $f(x)$ . We must put a constant of integration because then all functions with this form of derivative are accounted for.