Intermediate Algebra Summery

Since .5 is in the domain of the arctan and these function are inverse operations the answer is .5 4) Cos-1 (Cos 240o) = x Since 240o is not in the range of arccos, we need to do this in two steps. Cos 240o = -.5, thus Cos-1 (-.5) = 120o . ................
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