... shownthatPsn/2=D(0,- 1), P13n/2=B(0, 1), P_15n/4=ECV2/2,V2/ 2), P_17n/6=F(-V3I2,-1/ 2). Consequently,sin (3 n/ 2) =-1,cos (3 n/ 2) = 0;sin (1 3n/ 2) = 1, cos (1 3n/ 2) ==0;sin (- 15n/ 4) = v2/2,cos (- 15n/ 4) =Y2/2;sin (- 17n/ 6) =-1/2,cos (- 17n/ 6) = ... 3/2.-1/ 2), Pl1 n/6(V 3/2,-1/ 2), thereforetan (3 n/ 4) =cot (3 n/ 4) =-1,tan (1 7n/ 4) =cot (1 7n/ 4) = 1,tan (- 17J1/ 6) = 1/V3 z.z:V3/;~,cot (- 17J1/ 6) = V3,tan (1 1Jr/ 6) = - y3/3,cot (1 1n/ 6) ==-Y3.~1.3.BasicPropertiesofTrigonometricFunctions1.Periodicity.AfunctionIwithdomainofdefinitionX ... del-initionofthefunctionf (x).Thedefinitionofthefunc-tiong (x)impliesthattheequalitiesg (x - t) =g(x)= g (x + t)andf(xV5- tVS) = f (xVS) =f (xV5"+ tV" 5) areequivalent.Therefore,sinceT...