MHB How to graph complex number fractions

Click For Summary
When graphing the complex number (3+4i)/25 on a complex plane, the x-coordinate is 3/25 and the y-coordinate is 4/25, not 4i/25. The real numbers are plotted on the x-axis and the imaginary numbers on the y-axis. To locate the point, draw a vertical line at 3/25 on the x-axis and a horizontal line at 4/25 on the y-axis. The intersection of these lines represents the complex number. The correct terminology is to refer to these as coordinates rather than points.
Raerin
Messages
46
Reaction score
0
If I'm graphing (3+4i)/25, would the x-point be 3/25 and the y-point be 4i/25?
 
Mathematics news on Phys.org
Raerin said:
If I'm graphing (3+4i)/25, would the x-point be 3/25 and the y-point be 4i/25?

Hi Raerin, :)

If you are marking the complex number \(\frac{3}{25}+i\frac{4}{25}\) on a complex plane you will have your real numbers on the x-axis and your imaginary numbers on your y-axis. First you will have to find \(\frac{3}{25}\) on the x-axis, draw a vertical line through that point. Then find \(\frac{4}{25}\) on the y-axis and draw a horizontal line through that point. The point where these two lines intersect would represent the complex number \(\frac{3}{25}+i \frac{4}{25}\).
 
Raerin said:
If I'm graphing (3+4i)/25, would the x-point be 3/25 and the y-point be 4i/25?
No quite but almost. You are just saying it wrong. It not "x point" and "y point" but "x coordinate" and "y coordinate" of the single point representing the complex number.

The x coordinate is 3/25 and the y coordinate is 4/25 (NOT "4i/25": numbers on the graph, being distances on a line, are real, not imaginary).

In general, the point representing a+ bi is (a, b), with x coordinate a and y coordinate b.
 
I have been insisting to my statistics students that for probabilities, the rule is the number of significant figures is the number of digits past the leading zeros or leading nines. For example to give 4 significant figures for a probability: 0.000001234 and 0.99999991234 are the correct number of decimal places. That way the complementary probability can also be given to the same significant figures ( 0.999998766 and 0.00000008766 respectively). More generally if you have a value that...

Similar threads

  • · Replies 19 ·
Replies
19
Views
3K
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
Replies
2
Views
1K