Question #38c7a

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Answer 1 · 2017-11-20T11:39:57

Convert Radians to Degrees

#pi=180#

#((-5(180))/6)=-150#

cos(-150)
Get coterminal

cos(360+-150)
cos(210)

Get Reference angle
cosine is on quadrant III therefore its negative

#-cos(30)=-sqrt3/2#