1.0 不 △sin0 0.8- 0 uis 0.6- △0→ 0.4- 0.2 0.0 0 20 40 60 80 0(degrees) △d △2 △0cos0 The fractional error approaches d 几 sin0 zero as 0 approaches 900.     sin  cos     d d The fractional error approaches zero as  approaches 90o