Should I write $i$ before or after the imaginary part?

Should I write complex numbers as $a+ib$ or $a+bi$? Maybe there are certain cases where I should write it one way and other cases where I should write it the other way. What do you think?

Solution 1:

It's really a matter of style, but I typically see integer factors written first, then other real constants, then $i$, then variables. Thus you might have $2\pi inx$.

Solution 2:

If the imaginary part is a number, say 2, clearly it is better to write it as $2i$ rather than $i2$.

If the imaginary part is a "variable" or represented by a letter, then it is up to your personal preference. $x+iy$, $e^{i\theta}$ seems to be more common than $x+yi$, $e^{\theta i}$ though.