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

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