Respuesta :
Answer:
Option C and D are correct options
Step-by-step explanation:
The correct options are C and D.
We know that i = √-1
i² = -1
i³ = -i
and i^4 = 1
Lets solve the options one by one:
i^6 =1
Break the power:
i² *i ² * i² = (-1)(-1)(-1)
= -1
Therefore A is wrong
B) i^18 = 1
Lets break the power:
i²* i² *i² *i²*i²*i²*i²*i²*i²
put the value of i^2
= (-1) (-1) (-1) (-1) (-1) (-1) (-1) (-1)(-1)
= -1
Therefore option B is incorrect.
C) i^7 = -i
= i² * i² *i² *i
=(-1) (-1) (-1) * √-1
= - √-1
We know that √-1 = i
So,
- √-1 = -i
Therefore option C is correct.
D) i^16 = 1
= i² * i² * i² * i² * i² * i² *i² *i²
= (-1) (-1) (-1) (-1) (-1) (-1) (-1) (-1)
= 1
Therefore option D is correct.
Thus option C and D are correct option....
Answer: Option C and Option D
Step-by-step explanation:
Remember that by definition we have to:
[tex]i=\sqrt{-1}[/tex] and [tex]i^2=-1[/tex]
So for the option A we have to:
[tex]i^6=(\sqrt{-1})^2*(\sqrt{-1})^4\\\\i^6=-1*(-1)^2\\\\i^6=-1[/tex]
Option A is false
So for the option B we have to:
[tex]i^{18}=(i^6)^3[/tex]
We know that [tex]i^6=-1[/tex]
So
[tex]i^{18}=(-1)^3[/tex]
[tex]i^{18}=-1[/tex]
Option B is false
So for the option C we have to:
[tex]i^7=(i)^6*i^1[/tex]
[tex]i^7=-i[/tex]
Option C is true
Finally for the option D we have to:
[tex]i^{16}=(i^4)^4[/tex]
[tex]i^{16}=((-1)^2)^4[/tex]
[tex]i^{16}=(1)^4[/tex]
[tex]i^{16}=1[/tex]
Option D is true