Flashcard 20 - Math Flashcard Set for the SAT Exam

\[i^{1} = i\] \[i^{2} = -1\] \[i^{3} = -i\] \[i^{4} = 1\]

The complex number \(i\) is defined as \(i=\sqrt{-1}\).

The first power of \(i\) is simply \(i^{1} = i\).

The second power of \(i\) is \(i^{2} = \sqrt{-1} \times \sqrt{-1} = -1\).

The third power of \(i\) is \(i^{3} = i^{2} \times i = –1 \times i = -i\).

The fourth power of \(i\) is \(i^{4} = i^{2} \times i^{2} = -1 \times -1 = 1\).