Question 1008289
Arcsin ( sin (2π/5) ) = (2pi/5)
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Arcsin ( cos ( 3π/7) ) = 0.2244
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sin (Arccos (-3/7)) = 0.9035
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arccos x = 2Arccos (3/4)
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Take the cos of both sides to get:
x = 0.125
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