Need help with complex numbers

abel muroi

Junior Member
Joined
Jan 13, 2015
Messages
210
I was given the problem i1002


Ok so..... since I know that i2 = -1

does that mean that i1002 = -1

if that's true then all imaginary numbers that have EVEN exponents will always equal to -1 and the ODD ones will equal to 1?
 
I was given the problem i1002


Ok so..... since I know that i2 = -1

does that mean that i1002 = -1

if that's true then all imaginary numbers that have EVEN exponents will always equal to -1 and the ODD ones will equal to 1?
i1 = i
i2 = -1
i3 = i2 i1 = -i
i4 = [i2]2 = [-1]2 = 1
i5 = i4 i = i
...
 
I was given the problem i1002


Ok so..... since I know that i2 = -1

does that mean that i1002 = -1

if that's true then all imaginary numbers that have EVEN exponents will always equal to -1 and the ODD ones will equal to 1?
Not quite! Of the EVEN exponents, those that are divisible by 4 turns (+1) and the rest turns into (-1). In other words i4n = 1 and i2(2n+1) = -1
 
i1 = i
i2 = -1
i3 = i2 i1 = -i
i4 = [i2]2 = [-1]2 = 1
i5 = i4 i = i
...

What if I divided the exponent with four? and used the remainder as an exponent?

for example...

i1002

4/ 1002 = 250 with the remainder of 2

so that means i1002 = -1 because i2 = -1

do you think this method makes sense?
 
Last edited:
What if I divided the exponent with four? and used the remainder as an exponent?
4/ 1002 = 250 with the remainder of 2
do you think this method makes sense?
In fact, that is the only method to make sense of this.

It will also work for negative exponents with one modification.
\(\displaystyle \dfrac{1}{i}=(i)^{-1}=-i\). Thus \(\displaystyle \dfrac{1}{i^{23}}=(i)^{-23}=(-i)^{23}=-i^3=i\)

\(\displaystyle \dfrac{1}{i^{34}}=(i)^{-34}=(-i)^{34}=i^2=-1\)
 
What if I divided the exponent with four? and used the remainder as an exponent?

for example...

i1002

4/ 1002 = 250 with the remainder of 2

so that means i1002 = -1 because i2 = -1

do you think this method makes sense?
4/1002 is not 250 R 2. Is 4/20 =5? Both of these numbers are less than 1. You need to know this! 20/4 = 5 and 1002/4 =250 R2.
 
Top