Answer:
TRUE
Step-by-step explanation:
A complex number is represented as z = x + iy
Given the complex number -5i, this can also be written as;
z = 0-5i
Get the modulus
|z| = √0²+(-5)²
|z| = √25
|z| = 5
Get the argument
theta = arctan(y/x)
theta = arctan(-5/0)
theta = arctan(-∞)
theta = -90degrees
Since tan is negative in the 2nd and fourth quadrant
in the fourth quadrant, theta - 360 - 90
theta = 270 degrees
Express in polar form;
z = |z|(cos theta + i sintheta)
z = 5(cos270°+ison270°)
Hence the statement given is TRUE
