Convert the complex number $z=12(\cos 90°+i\text{・}\sin 90°)$ from polar to rectangular form.

Express the complex number $z=7+11i$ in polar form.

Express the complex number $z=2-4i$ in the polar form.

Express the complex number $z=1-\frac{\sqrt{3}}{3}i$ in polar form.

Convert the complex number $z=\sqrt{2}(\cos \frac{7\pi }{4}+i\text{・}\sin \frac{7\pi }{4})$ from polar to rectangular form.