2i(-4-i)^2 multiply. find power of i, i^89?
This may sound stupid but I can't seem to know how to calculate the powers of i. It's seems easy but I just don't get the correct answer. Any tricks to find powers of i.
Thanks!
A-Best: i = sqrt(-1)
i^1 = i
i^2 = -1
i^3 = -i
i^4 = 1
i^5 = i
etc...
to figure out i^89, find the remainder of the ^# when divided by 4
89/4 = 1
i^89 = i
2i(-4-i)^2
2i(16+8i+i^2)
2i(16+8i-1)
32i - 16 - 2i
30i - 16
-16 + 30i
