Modulus of z1 z2 where z1 and z2 are complex:
A|z1| + |z2|
B|z1|/|z2|
C|z1| - |z2|
D|z1| × |z2|
Answer & Solution
Correct answer: D. |z1| × |z2|
Important property: |z1 z2| = |z1| × |z2|. Modulus is multiplicative. (Also |z1/z2| = |z1|/|z2| when z2 ≠ 0.)
Related questions
Using De Moivre's theorem, the complex roots of $z^3=1$ are:If $\alpha$ and $\beta$ are roots of $z^2+4z+8=0$, then $\dfrac{\alpha+\beta+4i}{\alpha\beThe locus $\left|\dfrac{z-2}{z+3i}\right|=4$ simplifies to which equation?Simplify i raised to the power 27. What is the result?Multiply (2 + 3i) by (4 - i). What is the product in standard form?How is the complex conjugate of a complex number obtained?Add the complex numbers 5 - 2i and 3 + 7i. What is the sum?In the complex number 7 + 4i, which part is the real part?