find the exact value of sin(-15pi/6) and cot(-7pi/6)

Answer 1

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 x-axis
= -1/tan 30°
= -1/(1/√3) = -√3

Answer 2

Thank youu(: