How do you find the exact value of sin(arctan(2))? Trigonometry Inverse Trigonometric Functions Inverse Trigonometric Properties 1 Answer Chandra S. Sep 7, 2015 Let alpha = arctan(2), then, we require the value of sinalpha . now tan alpha = 2 => sinalpha = 2/sqrt5. Explanation: tanalpha = 2 => y= 2a, x = 2a & r = sqrt (5a^2 ) = sqrt5 a sinalpha = 2a/ sqrt5 a = 2/sqrt5 Answer link Related questions How do you use the properties of inverse trigonometric functions to evaluate tan(arcsin (0.31))? What is \sin ( sin^{-1} frac{sqrt{2}}{2})? How do you find the exact value of \cos(tan^{-1}sqrt{3})? How do you evaluate \sec^{-1} \sqrt{2} ? How do you find cos( cot^{-1} sqrt{3} ) without a calculator? How do you rewrite sec^2 (tan^{-1} x) in terms of x? How do you use the inverse trigonometric properties to rewrite expressions in terms of x? How do you calculate sin^-1(0.1)? How do you solve the inverse trig function cos^-1 (-sqrt2/2)? How do you solve the inverse trig function sin(sin^-1 (1/3))? See all questions in Inverse Trigonometric Properties Impact of this question 11705 views around the world You can reuse this answer Creative Commons License