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 24885 views around the world You can reuse this answer Creative Commons License