Verified answer

Veja:

∫4.senx .cosx dx ,de 0 a pi/4=

u=senx

du=cosx dx

∫4.senx .cosx dx ,de 0 a pi/4=

4∫u du ,de 0 a pi/4=

4u²/2=

2u²=

2sen²x =

de 0 a pi/4:

2sen²45º-2sen²0

2(√2/2)²-0=

2.2/4=

1

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