# Question concerning experiment on heisenbergs uncertanity principle

1. The problem statement, all variables and given/known data
Hello guys my name is Mathias i’m 15 years and i have been tasked to show a little experiment in my school class. It’s concerning Heisenbergs principle, you have probably all heard about this demonstration. It’s basically firing a laser beam through a narrow passage, whereafter it will spread out due to σ x σ p ≥ h/4.
My problem is that theres an equation that i don’t understand, ill try and explain as well as i can as i cant use images.

So theres not really any big need for me to explain the experiment or anything else, but just the equation, so here it is:

ΔPx=$\frac{h}{\lambda}$Sin($\Phi$)=$\frac{h}{\lambda}$Tan-1($\frac{y}{x}$)

To me, this states that Sin($\Phi$)=Tan-1($\frac{y}{x}$). But that isnt right is it? So i cant figure out how this works out, i’ve looked up alot of trigonometry but nothing has helped me figure it out… Is it an error or is it me whos overlooking something?

If it’s ok i have allowed myself to add a link to the document. It is in danish, but looking at the graphics on the first 2 pages, visualises my problem.
h=Plancks Constant

Thanks in advance, hope you can help me!
– Mathias

http://ift.tt/1cSnukf