extrema of 7z_1^2 + 4 z_1 (0.5(1-z_1) - sqrt(0.25 - 0.75 z_1^2 + 0.5 z_1)) + 3 (0.5(1-z_1) - sqrt(0.25 - 0.75 z_1^2 + 0.5 z_1))^2 - 10 z_1 - 6 (0.5(1-z_1) - sqrt(0.25 - 0.75 z_1^2 + 0.5 z_1)) + 4