pustiti #cot ^ (- 1) theta = A # zatim
# RarrcotA = theta #
# RarrtanA = 1 / theta #
# RarrcosA = 1 / SecA = 1 / sqrt (1 + tan ^ 2A) = 1 / sqrt (1+ (1 / theta) ^ 2) *
# RarrcosA = 1 / sqrt ((1 + theta ^ 2) / theta ^ 2) = theta / sqrt (1 + theta ^ 2) *
# RarrA = cos ^ (- 1) (theta / (sqrt (1 + theta ^ 2))) = krevetić ^ (- 1) (theta) #
#rarrthereforecot ^ (- 1) (theta) = cos ^ (- 1) (theta / (sqrt (1 + theta ^ 2))) *
