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: , , -i, 111, and then back to i. This cycle repeats every 444 powers. So, to simplify i^{545454}, we can divide 545454 by 444 and look at the remainder to determine where we are in the cycle.
Determining the position in the cycle: Dividing 545454 by 444 gives us 131313 with a remainder of 222. This means that i54i^{54}i54 is equivalent to i(4⋅13+2)i^{(4\cdot 13 + 2)}i(4⋅13+2). Since i4=1i^4 = 1i4=1 (and any integer power of it), we can ignore the 4⋅134\cdot 134⋅13 part because it will just be 111 to any power, which is still 111.
Simplifying i54i^{54}i54 using i2i^2i2: Now we only need to consider i2i^2i2. Since i2=−1i^2 = -1i2=−1, i54i^{54}i54 simplifies to −1-1−1.
More problems from Domain and range of quadratic functions: equations