Visualizing Conjugates on the Complex Plane

We have established that a conjugate of a complex number is the same number with its imaginary part flipped. It is represented with an overline like z\overline{z} or conj(z)\text{conj}(z)as Algebraically we have;

z=a+biz = a + bi

z=abi\overline{z} = a - bi

The blue point represents a complex number zz and you can move it around. The red point represents its conjugate z\overline{z}

Visualizing a Conjugate

Some insights that you should be able to visually understand from this is that;

  • Conjugate is formed by flipping the number on the x-axis.
  • The magnitude of a complex number z|z|and its conjugate z|\overline{z}|is the same.
  • Conjugate of a real number is the same as itself.

Addition of Conjugates is Real

We know previously that; z+zRz + \overline{z} \in \mathbb{R} because the imaginary parts cancel out. Graphically we can see that z+zz + \overline{z} is a horizontal line meaning it has no imaginary component.

You can move the blue point around to see this in action.

Adding a Number and its Conjugate

Subtraction of Conjugates is Imaginary

We know previously that; zoverlinezIz - overline{z} \in \mathbb{I} because the real parts cancel out. Graphically we can see that zzz - \overline{z} is a vertical line meaning it has no real component.

You can move the blue point around to see this in action.

Subtracting a Number and its Conjugate


End of Lesson

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Addition on the Complex Plane
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Multiplication on the Complex Plane