Biểu diễn tín hiệu nào sau đây là không chính xác:

$x\left(e{}^{jm}\right)=\left|A\left(e{}^{jm}\right)\right|e{}^{j\varphi \left(m\right)}$

$x\left(e{}^{j\pi }\right)=\left|x\left(e{}^{j\pi }\right)\right|e{}^{j\text{\%}\left(\pi \right)}$

$X\left(e{}^{j\pi }\right)=A\left(e{}^{j\pi }\right)\cdot e{}^{j\varphi \left(\pi \right)}$

$x\left(c{}^{j\infty }\right)=\left|x\left(c{}^{j\infty }\right)\right|c{}^{j-\text{a}\text{r}\text{g}\left[X\left(c{}^{j+\infty }\right)\right]}$