Answer:
After solving we get [tex]\mathbf{i^3=-i}[/tex]
Option D is correct.
Step-by-step explanation:
We are given:
If [tex]i=\sqrt{-1}[/tex] we need to find the value of [tex]i^3[/tex]
Solving:
[tex]i=\sqrt{-1}[/tex]
Taking cube on both sides
[tex]i^3=(\sqrt{-1})^3\\[/tex]
We can write [tex]a^3= a^2.a^1[/tex] Using this for solving:
[tex]i^3=(\sqrt{-1})^2.(\sqrt{-1})\\We \ know \ (\sqrt{-1})^2 =- 1 \ and \ \sqrt{-1}=1 \\i^3=-1(i)\\i^3=-i[/tex]
So, after solving we get [tex]\mathbf{i^3=-i}[/tex]
Option D is correct.
