Question about phase factor in Quantum Mechanics

[grandpa2390]

Homework Statement

I am trying to understand a solution to a problem. I may not need to post the entire question, I just need to know if $-i = e^{\frac{-i*pi}{2}}$

Homework Equations

The Attempt at a Solution

the reason for this question is that one step of the problem has a quantity multiplied by -i and the next step changes it to the e^... and claims that it differs just by an overall phase.

If you need the entire question, I sincerely apologize.

 

[TSny]

I just need to know if $-i = e^{\frac{-i*pi}{2}}$

Yes. See https://en.wikipedia.org/wiki/Euler's_formula