Q. Which of the following is equivalent to the complex number i54 ?Choose 1 answer:(A) 1(B) i(C) −1(D) −i
Definition of i: To solve for i54, we need to remember that i is the imaginary unit, which is defined by i2=−1. We can use the powers of i to simplify i54.
Cycle of powers of : The powers of repeat in a cycle: , −1, , 1, and then back to . This cycle repeats every 4 powers. So, to simplify 54}, we can divide 54 by 4 and look at the remainder to determine where we are in the cycle.
Determining the position in the cycle: Dividing 54 by 4 gives us 13 with a remainder of 2. This means that i54 is equivalent to i(4⋅13+2). Since i4=1 (and any integer power of it), we can ignore the 4⋅13 part because it will just be 1 to any power, which is still 1.
Simplifying i54 using i2: Now we only need to consider i2. Since i2=−1, i54 simplifies to −1.
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