Solve i14+i15+i16+i17= ?

A) 0
B) 1
C) 2i
D) 1i
E) 2+2i

2 Answers

0.

Explanation:

i14=i2=1
i15=i14i=1×i=i
i16=i15i=i×i=1
i17=i16i=1×i=i

Therefore, 1i+1+i=0

So option A is correct.
Generally sum of any four consecutive powers of i is 0.

May 12, 2018

Answer A: 0

Explanation:

Every i2=1
So we rewrite, taking out the i's two by two:

=(1)7+(1)7i+(1)8+(1)8i

Every even power of 1 will give +1, and every odd power will give 1. Rewrite again:

=1+(1)i+1+1i

And you'll see they all cancel out.