From my understanding you want to convert the mathematical equations provided in the picture into MATLAB code. Here is the code which might help you:
ra=[0 0.3 0.12]
rb=[0 0.35 0.15]
omega=[0 1.5 2.6]
ab=[0 -2.73 1.575]
%omega x (omega x ra)
omegaCrossra = cross(omega,cross(omega,ra))
%2*omega x Vrel
vrel=cross([0 8 0],[0 0.3 0.12])
twoTimesOmegaCrossVrel = cross(2*omega,vrel)
%p x (p x ra)
p=[0 8 0]
arel = cross(p,cross(p,ra))
x=norm(p)
aa=ab+omegaCrossra+twoTimesOmegaCrossVrel+arel
%Magnitude of aA
magnitudeaa=norm(aa)
%angular acceleration
alpha=cross(omega,[0 9.5 2.6])
Please refer to cross product for more information on cross products of vectors and norm documentation for calculation of magnitude of the vector.
