The tight binding energy dispersion (e-k) relation for electrons in a one-dimensional array of atoms having lattice constant a and total length l is e eo--2y co

The tight binding energy dispersion (E-k) relation for electrons in a one-dimensional array of atoms having lattice constant a and total length L is E Eo--2y cos (ka), where Eo, B and y are constants and k is the wave vector. The density of states of electrons (including spin degeneracy) in the band is given by (a) L Ty a sin(ka) L L 277y a sin{ka) 2.7y a cos{ka) (d)- ty a cos(ka)