Question

Plot the complex number 5i and find its absolute value

Answer 1

Check the picture below.

$\bf 5i\implies \stackrel{a}{0}~~\stackrel{b}{+5}i\implies \stackrel{\stackrel{absolute~value}{modulus}}{r=\sqrt{a^2+b^2}}\implies r=\sqrt{0^2+5^2}\implies r=5$