Question 520738
Use references angles to find the exact value of each expression. Sin 300


  sin 300= sin (180+120)
         = sin(180)cos(120) + sin(120)cos(180)     
         = 0*cos(120) + sin(120)(-1)
         = -1sin(120)  
         = -1sin(180-120)  since the sinus of two supplementary angles are the same.

so sin 300= -1sin60
          = -(sqrt 3)/2