About this video
The video plots complex numbers on the complex plane, where the horizontal axis shows the real part and the vertical axis shows the imaginary part. It plots -2 + 2i, 5 + 2i, 1 + 5i and 4 - 4i.
You'll be able to
- say which axis of the complex plane shows the real part and which shows the imaginary part.
- plot a complex number a + bi on the complex plane.
Key words
- complex plane
- A grid with the real part on the horizontal axis and the imaginary part on the vertical axis.
- real part
- The part of a complex number not multiplied by i; for -2 + 2i it is -2.
- imaginary part
- The multiple of i in a complex number; for -2 + 2i it is 2.
Transcript
Move the orange dot to negative 2 plus 2i. So we have a complex number here. It has a real part, negative 2. It has an imaginary part, you have 2 times i. And what you see here is we're going to plot it on this two-dimensional grid, but it's not our traditional coordinate axes.
In our traditional coordinate axis, you're plotting a real x value versus a real y-coordinate. Here on the horizontal axis, that's going to be the real part of our complex number. And our vertical axis is going to be the imaginary part. So in this example, this complex number, our real part is the negative 2 and then our imaginary part is a positive 2.
And so that right over there in the complex plane is the point negative 2 plus 2i. Let's do a few more of these. So 5 plus 2i. Once again, real part is 5, imaginary part is 2, and we're done. Let's do two more of these. 1 plus 5i. 1-- that's the real part-- plus 5i right over that Im.
All right, let's do one more of these. 4 minus 4i. Real part is 4, imaginary part is negative 4. And we're done.
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