How do you find exact value with out calculator #1-tan^2 10+ csc^2 80#? Trigonometry Right Triangles Trigonometric Functions of Any Angle 1 Answer Manikandan S. Feb 8, 2015 Try this method #t = 1-tan^2(10^0)+csc^2(80^0)# # = 1-tan^2(10^0)+csc(90^0-10^0)^2# #=1-tan^2(10^0)+sec^2(10^0)# #=1+(1-sin^2(10^0))/cos^2(10^0)# #=1+1# #=2# Answer link Related questions How do you find the trigonometric functions of any angle? What is the reference angle? How do you use the ordered pairs on a unit circle to evaluate a trigonometric function of any angle? What is the reference angle for #140^\circ#? How do you find the value of #cot 300^@#? What is the value of #sin -45^@#? How do you find the trigonometric functions of values that are greater than #360^@#? How do you use the reference angles to find #sin210cos330-tan 135#? How do you know if #sin 30 = sin 150#? How do you show that #(costheta)(sectheta) = 1# if #theta=pi/4#? See all questions in Trigonometric Functions of Any Angle Impact of this question 12177 views around the world You can reuse this answer Creative Commons License