# Linear Algebra - what is Re and Im for complex numbers??

## Homework Statement

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## The Attempt at a Solution

I don't even know what these are, it is not outlined in my textbook. I'm assuming Im is image? But how do you calculate image even?

As far as I'm concerned Im has to do wtih linear transformations - i have no clue how to calculate it. I am looking around online but I can't even find guidance.

DrClaude
Mentor
Re is the real part, and Im is the imaginary part:
$$\textrm{Re}(a + i b) = a \\ \textrm{Im}(a + i b) = b$$
(assuming ##a,b \in \mathbb{R}##).

Arnoldjavs3
Re is the real part, and Im is the imaginary part:
$$\textrm{Re}(a + i b) = a \\ \textrm{Im}(a + i b) = b$$
(assuming ##a,b \in \mathbb{R}##).

Oh! That makes this easy then. Is this notation common then? They could have saved me the trouble of typing out a few more characters... :)

DrClaude
Mentor
The notation is quite common. Another common notation is ##\Re## and ##\Im##.

Arnoldjavs3