How do you write the function in terms of the cofunction of a complementary angle tan(pi/5)? Trigonometry Graphing Trigonometric Functions Applications of Radian Measure 1 Answer Massimiliano Mar 4, 2015 The answer is: cot(3/10pi). tan(pi/5)=cot(pi/2-pi/5)=cot(3/10pi). Answer link Related questions What are some applications of using radian measure? How do you calculate the length of an arc and the area of a sector? How do you approximate the length of a chord given the central angle and radius? What are some example problems involving angular speed? How do you find the length of the chord of a circle with radius 8 cm and a central angle of 110^@? How does sinx=0 equals π? What is the value of sin(pi/4)? What is the value of tan(pi/3)? What is the value of cos(7pi/4)? What is sin(pi/6)? See all questions in Applications of Radian Measure Impact of this question 25510 views around the world You can reuse this answer Creative Commons License