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avatar+318 

Use an Addition or Subtraction Formula to find the exact value of the expression, as demonstrated in Example 1.

sin

(43π/

12)

 Dec 4, 2019
 #1
avatar+129852 
+1

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

 

 

 

cool cool cool

 Dec 4, 2019

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