Question

If $i{z}^3+z^2-z+i=0$, then find $|z|$ ?

• A. 1
• B. 2
• C. 4
• D. 5

Answer 1

The correct option is A 1

Given, $i{z}^3+z^2-z+i=0$
Divide by $i$
$\Rightarrow z^3-i{z}^2+iz+1=0\Rightarrow (z-i)(z^2+i)=0$
$\Rightarrow z^2=-i$

$\Rightarrow z=i\sqrt{i}$

$\Rightarrow |z|=1$