1) cos4z + 2sin^22z = cos^2(2z) + 2(1-cos^2(2z)) = cos^2(2z) + 2 - 2cos^2(2z) = -cos^2(2z) + 2
2) (cos^2B + 2sinBcosB - sin^2B)^2 = (cos^2B + sin^2B + 2sinBcosB)^2 = (1 + 2sinBcosB)^2 = 1 + 4sin^2Bcos^2B + 4sinBcosB = 1 + 4sinBcosB(sinB + cosB)
1) cos4z + 2sin^22z = cos^2(2z) + 2(1-cos^2(2z)) = cos^2(2z) + 2 - 2cos^2(2z) = -cos^2(2z) + 2
2) (cos^2B + 2sinBcosB - sin^2B)^2 = (cos^2B + sin^2B + 2sinBcosB)^2 = (1 + 2sinBcosB)^2 = 1 + 4sin^2Bcos^2B + 4sinBcosB = 1 + 4sinBcosB(sinB + cosB)