document.write( "Question 786240: How do I prove cos(pi/6)=sqrt(3)/2 knowing that sin(pi/6)=1/2? \n" ); document.write( "

Algebra.Com's Answer #477843 by xinxin(76) $\"\"$ $\"About$

You can put this solution on YOUR website!
sin^2(x) + cos^2(x) = 1
\n" ); document.write( "sin^2(pi/6) + cos^2(pi/6) = 1
\n" ); document.write( "cos^2(pi/6) = 1 - sin^2(pi/6) = 1 - (1/2)^2 = 1 - 1/4 = 3/4
\n" ); document.write( "cos (pi/6) = sqrt (3/4) = sqrt(3)/2
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