If i2 = -1 and if a is a positive integer, which of the following must be equal to ia ?

Given that i^2 = -1, we can use this information to find the value of ia.

Step 1: Understand the problem The problem is asking us to find the value of ia given that i^2 = -1 and a is a positive integer.

Step 2: Use the given information We know that i^2 = -1. This is a fundamental property of the imaginary unit i in complex numbers.

Step 3: Apply the property of i We can write ia as i*a. Since a is a positive integer, it doesn't affect the sign of i. Therefore, ia is simply a multiple of i.

So, ia must be equal to ia.