Post Reply 
Roots of Complex Numbers (Sharp, TI, Casio)
12-31-2022, 08:26 PM
Post: #5
RE: Roots of Complex Numbers (Sharp, TI, Casio)
(12-31-2022 12:27 PM)Albert Chan Wrote:  z = |z| * e^(θ*i), where θ = arg(z)

(a^b)^c = a^(b*c)      → z^k = |z|^k * e^(kθ*i)

(12-30-2022 10:58 PM)Matt Agajanian Wrote:  Example Calculate 4th root of (15625+0.719413999i)

Let x= 15625, y=0.719413999

TI-30X Pro MathPrint:
[math] [P→Rx] (x^.25,y/4) → 11 [Real part]
[math] [P→Ry] (x^.25,y/4) → 2 [Imaginary part]
Thus, the answer is 11+2i

This example is in error, since (11 + 2i)^4 = 11753 + 10296i
This is what it mean:

(15625 * e^(0.719413999i)) ^ 0.25
= (15625 ^ 0.25) * e^(0.719413999i * 0.25)
≈ (11 + 2i)


Thanks!

Now that I know, how should I have entered my original expression in the 30X Pro MathPrint and 36X Pro?

Thanks
Find all posts by this user
Quote this message in a reply
Post Reply 


Messages In This Thread
RE: Roots of Complex Numbers (Sharp, TI, Casio) - Matt Agajanian - 12-31-2022 08:26 PM



User(s) browsing this thread: 2 Guest(s)