An array of 10 isotropic elements are placed along the z-axis a distance d apart. Assuming uniform distribution, find: a) the progressive phase (in degrees), b) half-power beamwidth (in degrees), c) first-null beamwidth (in degrees), for d) first side lobe level maximum beamwidth (in degrees), e) relative side lobe level maximum (in dB), and f) directivity (in dB) 1) broadside 2) ordinary end-fire