Complex Number Kookiness 7
Observe the table below. Can you find something interesting in any 1 of the 2 columns?
Complex Numbers |
Absolute Values of Complex Numbers Squared |
½+i |
1¼ |
½+2i |
4¼ |
½+3i |
9¼ |
½+4i |
16¼ |
½+5i |
25¼ |
½+6i |
36¼ |
½+7i |
49¼ |
½+8i |
64¼ |
The fraction ½ is added to consecutive integers multiplied by the imaginary unit i in the left column so that the squares of the absolute values
of the complex numbers are equal to the squares of the consecutive integers + ¼! If the real & imaginary parts of the complex numbers swapped values,
then their absolute values would stay exactly the same! The signs of the real part & imaginary part of each complex number doesn't matter because that won't
change the absolute value!
Complex Numbers |
Absolute Values of Complex Numbers Squared |
1+½i |
1¼ |
2+½i |
4¼ |
3+½i |
9¼ |
4+½i |
16¼ |
5+½i |
25¼ |
6+½i |
36¼ |
7+½i |
49¼ |
8+½i |
64¼ |
Below is a copy of the 1st table, except that this time, I printed the conjugates of the complex numbers!
Complex Numbers |
Absolute Values of Complex Numbers Squared |
½-i |
1¼ |
½-2i |
4¼ |
½-3i |
9¼ |
½-4i |
16¼ |
½-5i |
25¼ |
½-6i |
36¼ |
½-7i |
49¼ |
½-8i |
64¼ |
The main difference between a complex number & its conjugate is that the plus sign in the middle becomes a minus; or if it's already a minus, it becomes a plus!
Here are the conjugates of the ones for the 2nd table:
Complex Numbers |
Absolute Values of Complex Numbers Squared |
1-½i |
1¼ |
2-½i |
4¼ |
3-½i |
9¼ |
4-½i |
16¼ |
5-½i |
25¼ |
6-½i |
36¼ |
7-½i |
49¼ |
8-½i |
64¼ |
By the way, |a+bi| = |a-bi| = |-a+bi| = |-a-bi|;
all 4 of those are exactly the same!(In absolute value) You can have the variables a & b swap places without changing the absolute value!
The absolute value of a complex number:
Finally, here's the appropriate formula for this math trick:
|½ ± Ni|2 = |N ± ½i|2 = N2 + ¼
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© Derek Cumberbatch