Hello I need help

If the bisection method is applied with starting interval [2^m,2^*m+1)], where m is a positive or negatie integer, how any steps should be taken to compute the root to full machine precision on a 32-bit word length computer?

I shouse use the formula n> (log(b-a)-log(error) ) / log(2)

but i have no idea how to use it

thank you