Using the unit circle, how do you find the value of the trig function: tan pi/6?

1 Answer
Oct 7, 2015

Find tan (pi/6) on the trig unit circle

Ans: (sqrt3)/3

Explanation:

On the trig unit circle, M being the terminal point of the arc (pi/6)
AT = tan (pi/6) (by definition)
OM = OA = R = 1 (definition of trig unit circle)
Mm = (OM)/2 = 1/2 (equilateral triangle)
Om = sqrt3/2 (height of equilateral triangle)

Triangle OAT and triangle OMm
(AT)/(Mm) = (OA)/(Om) --> AT = (Mm)((OA)/(Om))
tan (pi/6) = (1/2)(1/(sqrt3/2)) = (1/2)(2/sqrt3) = 1/(sqrt3) = (sqrt3)/3
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