Resposta:
#rarrcsc (theta / 2) = sqrt26 #
Explicació:
Aquí, #270^(@)##<## theta ##<##360^@#
# rarr135 ^ (@) ##<## theta / 2 ##<##180^@# Significa # theta / 2 # es troba en segon quadrant on #sin i csc # són positius.
# rarrcottheta = -12 / 5 #
# rarrtantheta = -5 / 12 #
# rarrcostheta = 1 / sectheta = 1 / sqrt (1 + tan ^ 2theta) = 1 / sqrt (1 + (- 5/12) ^ 2) = 12/13 #
#rarrcsc (theta / 2) = 1 / sin (theta / 2) = 1 / sqrt ((1-costheta) / 2) = 1 / sqrt ((1-12 / 13) / 2) = 1 / sqrt (1 / (26)) = sqrt26 #
