Use an Addition or Subtraction Formula to find the exact value of the expression, as demonstrated in Example 1.
sin
(43π/
12)
sin (43 pi / 12)
Convert this to degrees
43 pi/ 12 * 180 /pi =
(43/12) (180) = 645° = 645 - 360 = 285°
sin (285) = sin (150 + 135) =
sin150*cos 135 + sin 135 * cos 150 =
sin 30 cos 135 + sin 45 cos 150 =
(1/2) * (- √2/2) + ( √2/2) (- √3/2) =
- √2 - √6 - [ √2 + √6 ]
________ = _____________
4 4