What does cis mean in math

We call the "a" the "real part" and "b" is the "imaginary part. Obviously, you can't graph a complex number on a number line, since the number line contains only Real numbers. However, if you take two number lines and put them at right angles to each other, so that they cross on their zeroes, you can now graph a complex number. You use the horizontal number line to measure off the real part, and you use the vertical number line to measure off the imaginary part.

It's the same process we would use to graph the ordered pair 3,4 on a cartesian plane. I don't know if you've ever thought about this, but if you're graphing points on a cartesian plane, every point can be described with an x and y, but there is another way to describe the point. You can describe it using a magnitude and an angle.

The magnitude is its distance from the origin 0,0 , and its angle is the angle it makes with the positive x axis. In the same way, every complex number can be described using a magnitude and angle. How far is that point from the origin?

Well, it's three units right and four units up. But what about the angle? But wait a minute! As a matter of fact, it does mean that. That, hopefully, will answer your question "What is cis notation? The Problem Site. Quote Puzzler. Tile Puzzler. Loading profile Logged in as:. When complex numbers are written in polar form, on the other hand, addition and subtraction have always been a matter of converting the number back into rectangular, another tedious process.

The advantage of polar form, in terms of arithmetic operations, is that multiplication, division, and exponentiation are exceptionally simple. Any two complex numbers in polar form, and are multiplied as such:. The trigonometric functions of sine and cosine are cyclical that is, periodic. It is important to realize that any given complex number on a complex plane can be arrived at by rotating around the pole a multitude of times.

It is easier to see in polar form, the number. This is a fundamental concept in trigonometry that extends into complex analysis. When performing arithmetic on polar complex numbers such that the angle of the solution is changed, it is essential to include the infinite number of rotations before manipulating the angle.

In this way, multiple angles can be computed and thusly multiple complex solutions for the original arithmetic operation. Math Wiki Explore. Browse content. Register Don't have an account? View source.