sin(4x)=2sin(2x)cos(2x)=4sin(x)cos(x)(2cos2(x)-1).
sin(x)/sin(4x)=1/(8cos3(x)-4cos(x)).
The indefinite integral of sin(x)/sin(4x) can be described as the area beneath the curve; but the curve is not continuous because for x=nπ/4 where n is an integer, the expression is undefined (the denominator=0). This means that the integral will be undefined (infinite) for some values of x.
Therefore we need to evaluate ∫dx/(8cos3(x)-4cos(x)).
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