# Complex Numbers Quiz

The reciprocal of the number i is:

• -i
• 1
• i
• -1

The absolute value of the complex number z = a+ib is:

• $\sqrt{z.\overline{z}}$
• a+b
• $z.\overline{z}$
• ${a}^{2}+{b}^{2}$

If z = a+ib is a complex number, then:

• $\mathrm{Re}\left(z\right)=\frac{z.\overline{z}}{2}$
• $\mathrm{Re}\left(z\right)=z+\overline{z}$
• $\mathrm{Re}\left(z\right)=\frac{z-\overline{z}}{2}$
• $\mathrm{Re}\left(z\right)=\frac{z+\overline{z}}{2}$