#sin x = 0.7#
First, calculator gives #x = 44.42 deg#.
The trig unit circle gives another arc #x = 180 - 44.42 = 135. 58 deg#, that has the same #sin# value #(0.7)#. Within the interval #(-180, +180)#, there are 2 answers: #x_1 = 44.42 deg# #x_2 = 135.58deg#