Exact value of arccos(-sqrt3/2)?

Question

inverse tan(-sqrt3)

Any help would be appreciated.

Answer 1

If cosθ = x, then arccos x = θ.

θ = arccos(-√3 / 2)
cosθ = -√3 / 2

θ = 5π/6, 7π/6 on the interval [0, 2π]
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θ = arctan(-√3)
tanθ = -√3

θ = 2π/3, 5π/3 on the interval [0, 2π]