SOLUTION: evaluate tan 13pi/12

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Question 984483: evaluate tan 13pi/12
Answer by srinivas.g(540) About Me  (Show Source):
You can put this solution on YOUR website!
pi = 180 degrees
13%2Api%2F12+=+13%2A180%2F12+
=+195 degrees
hence tan (13pi/12)= tan(195)
tan(195)= tan (180+15)
= tan(15)
tan(15) = tan(60-45)
= %28tan%2860%29-tan%2845%29%29%2F%281%2Btan%2860%29%2Atan%2845%29%29
= %28sqrt%283%29-1%29%2F%281%2Bsqrt%283%29%2A1%29
Multiply numerator and denominator by 1-sqrt%283%29 to get:
%281-sqrt%283%29%29%5E2%2F%281-3%29
= %281-2sqrt%283%29%2B3%29%2F2
= %284-2sqrt%283%29%29%2F2
= 2-sqrt%283%29
Result : 2-sqrt%283%29