Question: in trigonometry what is the inverse function of cosine?
Answer: The domain of the inverse cosine function is [−1,1] and the range is [0,π] . That means a positive value will yield a 1st quadrant angle and a negative value will yield a 2nd quadrant angle. The domain of the inverse tangent function is (−∞,∞) and the range is (−π2,π2) .