How do you calculate sin^-1(-sqrt2/2)? Trigonometry Inverse Trigonometric Functions Inverse Trigonometric Properties 1 Answer bp Apr 30, 2015 225, 315 degrees It is known that sin 45=sqrt(2)/2. Hence, sin^-1 (-sqrt(2)/2) would be either in the IIIrd quadrant that is 180+45= 225 degrees or in the IVth quadrant, that is 360-45=315 degrees . These are the two values of the angle between 0 to 2pi. 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 5745 views around the world You can reuse this answer Creative Commons License