Hello everyone,
I am trying to prove the following trigonometric identity, but I am not getting the answer given by my textbook:
Could somoene please comment on my work?
Thank you very much.
*This question actually comes from my attempt to integrate
, where
. I arrived at the LHS of (*) and am trying to get the RHS.
----------------
My work:
.
1. The last expression doesn't match the textbook's given answer.
2. Also, could someone please justify the removal of the absolute value sign for the second term on the RHS
?
I know that
so I can remove the absolute sign for this term, but
is both negative and positive on this interval.