Question

How do you evaluate sin(arccos(-1/3))?

Answer 1

Evaluate sin (arccos (-1/3)

Ans: `+- (2sqrt2)/3`

Explanation:

`cos x = -1/3` --> Radius of trig circle R = 3

`sin^2 x = R^2 - cos^2 x = 9 - 1/9 = 8/9` --> `sin x = +- (2sqrt2)/3`

`sin (arccos (-1/3)) = +- (2sqrt2)/3`