Tricky complex numbers problem

Click For Summary
SUMMARY

The discussion centers on rotating the complex number z2 = i - 5 around the point z1 = 1 + i by an angle of 45 degrees (π/4 radians). To achieve this, one must first calculate the difference z2 - z1, which is essential for determining the new position after rotation. The rotation is performed using the formula for complex multiplication, specifically multiplying by e^(iπ/4). The final step involves adding the rotated result back to z1 to find the new position of z2.

PREREQUISITES
  • Understanding of complex numbers and their representation in the complex plane
  • Familiarity with complex multiplication and rotation
  • Knowledge of Euler's formula, specifically e^(iθ)
  • Basic trigonometry, particularly angles in radians
NEXT STEPS
  • Study the properties of complex numbers in the complex plane
  • Learn about Euler's formula and its applications in rotations
  • Explore complex number transformations and their geometric interpretations
  • Practice problems involving rotations of complex numbers around arbitrary points
USEFUL FOR

Students studying complex analysis, mathematics enthusiasts, and anyone looking to deepen their understanding of geometric transformations in the complex plane.

andrew.c
Messages
46
Reaction score
0

Homework Statement



z1 = 1 + i, z2 = i − 5 are points in the complex plane. If z2 is rotated about z1 by 450
find its new position.

Attempt at solution
Absolutely no idea! I think I might need to use e^theta*i but not sure!
 
Physics news on Phys.org
What does that mean rotated about z1 by 450? Could you elaborate?
 
Sorry, that's all that was given...
I think it means like rotating 45 degs through the imaginary axis?
 
But then what does that have to do with Z1.
 
45 degrees is pi/4 radians. To rotate around another point, find the difference z2-z1 and rotate that by pi/4 (sure, multiply by e^(i*pi/4)). Add the result back to z1.
 
thank you!
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
Replies
39
Views
6K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 20 ·
Replies
20
Views
3K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
47
Views
4K
Replies
18
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 21 ·
Replies
21
Views
2K