Hi all,

For have implemented a program that performs the bisection method, currently with the user entering the initial interval to find one root. However I was wondering if I could get the program to find the intervals automatically without the users input.

The only way I can think to do this is by using the intermediate value theorem, and calculating the function values over a certain range.

E.g for x^2 - 9 = 0

f(-4) = 7

f(-3) = 0

f(-2) = -5

f(-1) = -8

f(0) = -9

so we know there is a root when the sign changes etc. so obviously I can tell this from looking, but I'm struggling for a way of how to get c++ to recognise this? Could anyone please give me a push in the right direction?

Thanks in advance!