I'm asked to find the phasor of this signal:
$$ x_1[n] = 3\sin\left(\frac \pi7 n\right) + 4j\cos\left(\frac \pi7 n\right),\quad (0\le n \le 20) \,.$$
The phasor is defined as:
$$ G z_{0}^{n}= Ae^{j\varphi}\cdot r^{n}\cdot e^{j\theta*n} = Ar^{n}[\cos(\theta n+\varphi)+ j\sin(\theta n+\varphi)] $$
But I really don't know how to make the conversion! I mean, one of them has a radius of 3, the other is 4. How can I do this?