Solution:
As per the question,
It is known that,
Provided that,
As a result,
As a result, 
As, ![\cos \theta \in[-1,1]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-da7cf54e794658ce031bef36184320ac_l3.png "Rendered by QuickLaTeX.com")
Therefore, 
As a result,
If 
Solution:
As per the question,
It is known that,
Provided that,
As a result,
As a result,
As,
Therefore,
As a result,