What is #cos^-1(1/2)#?

2 Answers
Aug 6, 2016

Answer:

#=60#

Explanation:

#cos^-1(1/2)#
#=60#

Aug 7, 2016

Answer:

#pi/3, and (5pi)/3#

Explanation:

#arccos x = 1/2#
Trig table of special arcs gives
#cos x = 1/2# --> #x = pi/3#
Trig unit circle gives another arc x that has the same cos value -->
#cos x = 1/2# --> #x = - pi/3#, or, #x = (5pi)/3# (co-terminal)
Answers: #pi/3 and (5pi)/3#