Problem involving complex numbers

In summary, the conversation discusses the expansion of a determinant and its relation to the equation w^2+w+1=0, where w is the cube root of 1. The solution set is found to be a straight line passing through points (0,0,0), (1,2,2), (2,4,4), etc. This is due to the cancellation of imaginary parts in the determinant.
  • #1
ubergewehr273
142
5

Homework Statement


Refer given image.

Homework Equations


Expansion of determinant.
w^2+w+1=0 where w is cube root of 1.

The Attempt at a Solution


Expanding the determinant I got cw^2+bw+a-c=0. Well after that I have no idea how to proceed.
 

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  • #2
ubergewehr273 said:

Homework Statement


Refer given image.

Homework Equations


Expansion of determinant.
w^2+w+1=0 where w is cube root of 1.

The Attempt at a Solution


Expanding the determinant I got cw^2+bw+a-c=0. Well after that I have no idea how to proceed.

If the determinant is going to be zero then the imaginary parts must cancel. What does that tell you?
 
  • #3
Dick said:
If the determinant is going to be zero then the imaginary parts must cancel. What does that tell you?
I compared the real and imaginary parts separately and ended up with the relation a=2b=2c.
 
  • #4
ubergewehr273 said:
I compared the real and imaginary parts separately and ended up with the relation a=2b=2c.

Ok, so what does that tell you about the geometry of the solution set?
 
  • #5
Dick said:
Ok, so what does that tell you about the geometry of the solution set?
Solution set includes (0,0,0) , (1,2,2), (2,4,4) and so on. This then gives a straight line. Thanks :bow:
 
  • #6
ubergewehr273 said:
Solution set includes (0,0,0) , (1,2,2), (2,4,4) and so on. This then gives a straight line. Thanks :bow:

Correct! You're very welcome.
 

1. What are complex numbers and how are they represented?

Complex numbers are numbers that are expressed in the form of a + bi, where a and b are real numbers and i is the imaginary unit (√-1). These numbers are represented on a complex plane, where the real part is represented on the horizontal axis and the imaginary part is represented on the vertical axis.

2. What is the purpose/application of complex numbers in science?

Complex numbers are used in various scientific fields, such as engineering, physics, and mathematics. They are particularly useful in solving problems involving AC circuits, quantum mechanics, and signal processing.

3. How are complex numbers added, subtracted, multiplied, and divided?

To add or subtract complex numbers, we simply add or subtract the real and imaginary parts separately. To multiply complex numbers, we use the FOIL method (First, Outer, Inner, Last). To divide complex numbers, we use the conjugate of the denominator to rationalize the fraction.

4. How do we solve equations involving complex numbers?

To solve equations involving complex numbers, we use the properties of complex numbers and algebraic manipulation. The goal is to isolate the variable on one side of the equation, just like solving any other algebraic equation.

5. Can complex numbers have exponents and roots?

Yes, complex numbers can have exponents and roots. The rules for simplifying these expressions are similar to those for real numbers, but we also need to use the properties of the imaginary unit i.

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