1.
If 3+isin⁡θ4−icos⁡θ\dfrac{3 + i\sin\theta}{4 - i\cos\theta}, θ∈[0,2π]\theta \in [0, 2\pi], is a real number, then an argument of sin⁡θ+icos⁡θ\sin\theta + i\cos\theta is: