As shown in the figure, it is known that the unit circle O and y-axis intersect at two points a and B. the vertex of angle θ is the origin, the starting edge is on the positive half axis of x-axis, and the ending edge is on the ray OC. The function value of the directed line AC is () A. sinθB. cosθC. tanθD. cotθ
In the right triangle OAC, Tan ∠ AOC = ACoA = AC, ∧ AC = Tan ∠ AOC = Tan (θ - π 2 & nbsp;) = - cot θ, so D