Posted by Purplechick4 on Monday, February 6, 2012 at 9:28pm.
find the exact value of sin(15pi/6) and cot(7pi/6)

PreCalc  Reiny, Monday, February 6, 2012 at 10:00pm
Perhaps you can "think" better in degrees than radians, sometimes I can.
sin(15π/6)
= sin(450°)
= sin(90) , I took away one rotation
= sin(90°) = 1
cot (7π/6)
= cot(210°)
= cot(150°) , 150 and 210 are coterminal
=  cot(30°) , 150 is in II and by CAST rule cotangent is negative, and 30° from the xaxis
= 1/tan 30°
= 1/(1/√3) = √3

PreCalc  Purplechick4, Monday, February 6, 2012 at 10:09pm
Thank youu(:
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