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  
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
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  
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COMENTÁRIO DA PROVA - MATEMÁTICA
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

  

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 
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 
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 
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 
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 

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
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

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COMENTÁRIO
- ASSUNTO: FUNÇÃO TRIGONOMÉTRICA

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

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2 . sen2x – 3 senx + 1 = 0
 
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− ( − 3) ± ( − 3)2 − 4 . 2 . 1
 

senx =
2.2
 
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 
3± 1 3±1

=
senx =
4
4
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

1
senx
=
1
ou
senx
=
.

2
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

1

2
,
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• Admitindo que senp = 1 e senq = 2 teremos cos
 q = ±

3 1


Daí sen2p – cos2q = 12 – = = 0,25.
4
2
3
3
 = .
2 
4
4
1

• Admitindo que senp = 2 e senq = 1, teremos cos2q = 0.
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 1 2
1
Daí sen2p – cos2q =  2  – 0 = 4 = 0,25.
Item: B