Odgovor:
# X = pi / 3 + 2kpi #
# X = -piperidm- / 3 + 2kpi #
Obrazloženje:
# 2cos ^ 2x + 3cos-2-0 #
#sqrt (Δ) = sqrt (25) = 5 #
# T_1 = (- 3-5) / 4 = -2 #
# T_2 = (- 3 + 5) / 4 = 1/2 #
# Cosx = 1/2 #
# X = pi / 3 + 2kpi #
# X = -piperidm- / 3 + 2kpi #
k je stvaran