The Modulus (Leaving Cert Mathematics): Flashcards

Distance from origin on Argand diagram

$|z| = \sqrt{a^2 + b^2}$

Absolute value bars: $|z|$ or $|a + bi|$

Non-negative real number

Pythagoras' theorem

Length of line segment from origin to point

$|z_1| + |z_2| \geq |z_1 + z_2|$

Sum of individual moduli always $\geq$ modulus of sum

Identify real & imaginary parts, then square both

Add the squares, then take square root

Positive

Its absolute value