Simplifying Complex Numbers: Solving for 2/i and Understanding i^-1

[Unassuming]

Homework Statement

Express 2/i in the form a + bi.

Homework Equations

The Attempt at a Solution

The book says -2i. What am I missing here? I don't see what they are using. All I get is 2i^-1.

Is i^-1 something that I don't know?

 

[Dick]

Multiply the numerator and denominator of 2/i by i.

 

[Unassuming]

ugh,...thanks Dick