Q. Which of the following is the correct form of −3i8−3i6−3i−1, where the imaginary number i is such that i2=−1?(A) −1(B) −1−3i(C) −7−3i(D) −1−3i
Simplify −3i8: We need to simplify each term involving i by using the fact that i2=−1. Let's start with the term −3i8. Since i4=(i2)2=(−1)2=1, we can simplify i8 as (i4)2=12=1. Therefore, −3i8 simplifies to −3×1=−3.
Simplify −3i6: Now let's simplify the term −3i6. Since i6=(i4)(i2)=1×(−1)=−1, we can simplify −3i6 as −3×(−1)=3.
Simplify −3i: The term −3i does not simplify further since it's already in terms of i to the first power. So, −3i remains as it is.
Simplify −1: The last term is −1, which also does not simplify further.
Combine simplified terms: Now we combine all the simplified terms: −3 (from −3i8) + 3 (from −3i6) −3i−1. This simplifies to (−3+3)−3i−1.
Final simplification: Combining like terms, we get 0−3i−1, which simplifies to −3i−1.