How do you evaluate tan (2Pi/3) + tan (Pi/4)? Trigonometry Right Triangles Trigonometric Functions of Any Angle 1 Answer Alan P. May 16, 2016 #tan((2pi)/3)+tan(pi/4)=color(blue)(1-sqrt(3))# Explanation: The angles #(2pi)/3# and #pi/4# are two of the "standard angles" for which you should be familiar with their ratios. (See images below). #tan((2pi)/3)=sqrt(3)/(-1)=-sqrt(3)# #tan(pi/4)=1/1=1# #tan((2p)/3)+tan(pi/4) = -sqrt(3)+1 = 1-sqrt(3)# 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 4593 views around the world You can reuse this answer Creative Commons License