Plotting of Lattice vibrations in diatomic linear chain

Trying to plot these dispersion curves in MATLB.

m1=1

m2=5

k=20

a=1

n=10

q=0:1*pi/a:pi/a

Need these equations : w1=w^2(q) and w2=-w^2(q)

plot (q,w1,q,w2)

Equation is:

02 MM, [(m, + M,)+ VM, + M; +2M,M,coska M wak) optical acoustic -r/a Ok N/a r