Problem about boundries in this solve of quantum problem

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The discussion centers on the boundaries in a quantum problem integral, specifically in spherical coordinates. The integral's limits are defined as r from 0 to infinity, θ from 0 to π, and φ from 0 to 2π. There is confusion regarding the origin of these boundaries, with a suggestion to clarify the use of trigonometric identities in the problem. The conversation emphasizes the distinction between "limit" or "bound" for numbers and "boundary" for curves or surfaces. Understanding these boundaries is crucial for solving the quantum problem effectively.
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hey

There is a problem about boundries in this solve of quantum problem. And I don't understand the boundries come from where on the integral.. I can not see it :( You will see in the picture... but If u want to see the other part of solve in problem I will add..
 

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hey opeth_35! :smile:

(btw, we say "limit" or "bound" for a number … "boundary" is for a curve or a surface :wink:)

the integral is over the whole of space, and it's in spherical coordinates,

so the limits are: r from 0 to ∞, θ from 0 to π, and φ from 0 to 2π

(i don't understand your second question, but maybe the answer is that they used one of the standard trigonometric identities … sin2θ = (1 - cos2θ)/2)
 
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