ATAR Notes: Forum

VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: ahat on May 27, 2013, 09:53:28 pm

Title: Complex Numbers: u = i^5z is found by...
Post by: ahat on May 27, 2013, 09:53:28 pm: A: reflecting z in the Im(z) axis
B: reflecting z in the Re(z) axis
C: reflecting z in the line Im(z) = Re(z)
D: rotating z through $/frac{pi}{2}$ about the origin (i.e. anticlockwise)
D: rotating z through - $/frac{pi}{2}$ about the origin (i.e. clockwise)

I'm fairly certain it is C:
i⁵ = i
therefore, u = xi - y

The thing is, I have to explain why all of the other options are correct. Heck, I have to explain why my option is correct. Because the x and y values have swapped....

Help appreciated
And I hope the text wraps work!
Title: Re: Complex Numbers: u = i^5z is found by...
Post by: ahat on May 27, 2013, 09:55:38 pm: Lol, my bad

D: rotating z through π/2 about the origin (i.e. anticlockwise)
E: rotating z through -π/2 about the origin (i.e. clockwise)
Title: Re: Complex Numbers: u = i^5z is found by...
Post by: brightsky on May 27, 2013, 11:14:11 pm: the answer should be D. i^5*z = i*z.