Question #0ad85 Trigonometry Graphing Trigonometric Functions Applications of Radian Measure 1 Answer Nghi N. Aug 20, 2016 0.416 Explanation: cos t = 0.8415 --> #cos ^2 t = 0.7081# Use trig identity: #cos 2a = 2cos^2 a - 1# #cos 2t = 2(0.7081) - 1 = 1.416 - 1 = 0.416# 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? How do you write the function in terms of the cofunction of a complementary angle #tan(pi/5)#? What is the value of #sin(pi/4)#? What is the value of #tan(pi/3)#? What is the value of #cos(7pi/4)#? See all questions in Applications of Radian Measure Impact of this question 1546 views around the world You can reuse this answer Creative Commons License