2.5. Find the half-power beamwidth (HPBW) and first-null beamwidth (FNBW), in radians and degrees, for the following normalized radiation intensities: (a) U(0) = cos cos(20) (b) U(0) = cos² cos² (20) (c) U(0) = cos(0) cos(30) (d) U(0) = cos²(0) cos² (30) (e) U(0) = cos(20) cos(30) (f) U(0) = cos² (20) cos² (30)) (0 << 90°,0<< 360°)