Generalised uncertainty Principle Can't get rid of the i?

[smileandbehappy]

Homework Statement

The Attempt at a Solution

As you can see where I have got up to... However I am stuck... In the solution there is no i. In mine there will be. I am unsure how you make the complex number drop out at this stage. I think I'm missing a mathematical trick here...

The solution should be: greater than or equal to (5h(bar)^2)/2. Clearly I am going to have an erroneous complex number in here...

Thanks

Sam

 

[fzero]

The notation $|\cdots|$ refers to the complex modulus, so you automatically have $|i|=1$.

 

[smileandbehappy]

The notation $|\cdots|$ refers to the complex modulus, so you automatically have $|i|=1$.

That's a bit embaressing... It is nearly 4am so let me off that one! Was reading it as the normal modulus making everything positive!

thanks - though, I was sititng scratching my head for half an hour at that.