Converting a Complex Number to Polar Form

In summary, the conversation discusses converting a complex number to polar coordinate representation. The solution is sqrt(2)e^-j45, with 45 degrees as the angle. The negative sign in front of the angle may seem confusing, but it is correct as the reference point for theta is the positive direction of the real axis. The conversation also mentions that the angle can be either positive or negative depending on the position of a and b in the imaginary/real plane.
  • #1
EvLer
458
0
Hello, I have this complex number that I need to convert to polar coord represntation:
z = 1 + j;
the answer is sqrt(2)e^-j45
(45 is degrees).
The part I don't undestand is negative before j45, since a and b are positive, I assumed it's in the first quandrant of Im/Re plane, and if the reference point for theta is real axis postive direction I do not see why there is a "-".
Thanks for explanation.
 
Physics news on Phys.org
  • #2
I'm sure it's a mistake.It should be

[tex]1+j=\sqrt{2}e^{+j\frac{\pi}{4}} [/tex]

Daniel.
 
  • #3
Thanks, that makes me happier :smile:
But generally, the "-/+" of the angle depends on the position of a and b in the im/real plane, so theta is counted from positive direction of real axis, like usually in geometry ... is it right?

Thank you again.
 
  • #4
Yes.Theta/the angle is anticlockwise.

Daniel.
 

1. What is a complex number?

A complex number is a number that contains both a real part and an imaginary part. It is written in the form a+bi, where a is the real part and bi is the imaginary part. For example, 3+4i is a complex number with a real part of 3 and an imaginary part of 4i.

2. What is the polar form of a complex number?

The polar form of a complex number is a representation of the complex number using its magnitude (or absolute value) and angle. It is written in the form re^iθ, where r is the magnitude and θ is the angle in radians. For example, the polar form of 3+4i is 5e^(0.927i).

3. How do you convert a complex number to polar form?

To convert a complex number to polar form, you can use the formula r = √(a^2 + b^2) and θ = tan^-1(b/a). Simply substitute the values for a and b from the complex number into the formula to find the magnitude and angle. Then, write the polar form using the values found.

4. Why is polar form useful?

Polar form is useful because it allows us to easily visualize and understand complex numbers. It also makes it easier to perform operations on complex numbers, such as multiplication and division, which can be more complicated in the standard form. Additionally, polar form is helpful in solving problems involving trigonometry and geometry.

5. Can all complex numbers be written in polar form?

Yes, all complex numbers can be written in polar form. This is because the magnitude and angle of a complex number can always be calculated using its real and imaginary parts. However, some complex numbers may have simpler or more complex expressions in polar form, depending on their values.

Similar threads

  • Precalculus Mathematics Homework Help
Replies
12
Views
992
  • Engineering and Comp Sci Homework Help
Replies
22
Views
2K
  • Precalculus Mathematics Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Precalculus Mathematics Homework Help
Replies
16
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
2K
Replies
8
Views
1K
  • Calculus and Beyond Homework Help
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
4K
  • Precalculus Mathematics Homework Help
Replies
9
Views
2K
Back
Top