Can you help me and for this exercise please!
the function f:(X,T)->(X,T') is continuous
the function f:(X,T')->(X,T) is open
{T is the Euclidean topology,T' is cofinite topology}
[the function f maybe is the identity function id but I am not sure]
please can you help me to prove this exercise;
Prove that:
the Euclidean topology R is finer than the cofinite topology on R
please answer me as faster as u can I have an exame on monday and I don't know to provethis exercise!