A compound inequality for the graph would be:
x >= 0 and x < 2
Sorry if my writing is sloppy
Note that
108° = 90° + 18°
so
sin(108°) = sin(90° + 18°) = sin(90°) cos(18°) + cos(90°) sin(18°) = cos(18°)
Then
sin²(108°) + sin²(18°) = cos²(18°) + sin²(18°) = 1
by the Pythagorean identity.
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