let me take a funtion that vanish at end points x=0 and x=L. do these functions qualify to be a vector space?
i proceeded this way - to show that they qualify, i have to show that they are closed, commutative etc. i think they are not closed. so they dont form vector space.am i correct??
how about periodic functions obeying f(0)=f(L)?(hints please)
and functions that obey f(0)=5?(hints please)