$$\cos \frac{2 \pi}{6} + \sin \frac{5 \pi}{6} =$$
we can write thisÂ
cos60 + sin150 =Â Â Â Â Â Â Â Â Â Â Â equation 1
and sin150 = sin( 90 + 60)Â
        = sin90co60 + cos90sin60
put sin90 = 1Â and cos60 = 1\2Â
we getÂ
sin150 = 1\2 and cos 60Â = 1\2Â Â Â Â Â Â Â put value in equation 1Â
cos60 + sin150 = 1\2 + 1\2 = 1       Answer   Â
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