Respostas

2014-05-04T00:18:41-03:00
X = pi/2

y = cos(2x) + sen(x)/ Tg(4x) - tg(x/2)

cos[2.(π÷2)] = -1
sen(π÷2) = 1
tg[4(π÷2)] = 0
tg[(π÷2)÷2]=-1

portanto 
y = 0÷(-1)
y=0

espero ter ajudado ^^
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