SOLUTION: How do I prove cos(pi/6)=sqrt(3)/2 knowing that sin(pi/6)=1/2?

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Question 786240: How do I prove cos(pi/6)=sqrt(3)/2 knowing that sin(pi/6)=1/2?
Answer by xinxin(76) About Me  (Show Source):
You can put this solution on YOUR website!
sin^2(x) + cos^2(x) = 1
sin^2(pi/6) + cos^2(pi/6) = 1
cos^2(pi/6) = 1 - sin^2(pi/6) = 1 - (1/2)^2 = 1 - 1/4 = 3/4
cos (pi/6) = sqrt (3/4) = sqrt(3)/2