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Chapter 7: Inverse Functions and Equations
Finally, we get to the inverse cotangent: Y
π
π 2 1
y = cot -1x 0 -1
1
X
-1
The inverse cotangent function. The inverse cotangent function is derived from Tangent, and has a domain (x-values) equal to all real numbers. The range is from 0 # y # π with y ≠ π and y ≠ 0, those horizontal lines being its two vertical asymptotes. Its graph is shown in the above figure. Two identities apply, as follows: Cot - 1 x = Tan - 1 1 x when x > 0 Cot - 1 x = π + Tan - 1 1 x when x < 0