User contributions for Dbmalesani
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1 March 2023
- 10:5110:51, 1 March 2023 diff hist +223 Talk:Sum of Arctangents No edit summary current
- 09:4309:43, 1 March 2023 diff hist +25 Talk:Sum of Arctangents No edit summary
- 09:3309:33, 1 March 2023 diff hist +716 N Talk:Sum of Arctangents Created page with "== Range of validity == This identity is not valid for any $a$, $b$. This is obvious as the right-hand side is bound to be in the interval $(-\pi/2,+\pi/2)$, while the left-hand side ranges in $(-\pi,+\pi)$. In the proof, the incorrect step is the last one, as it is not true that $\arctan\tan(\alpha) = \alpha$ if $|\alpha| \geqslant \pi/2$. I believe this identity is valid if $ab < 1$. It takes a similar form if $ab > 1$. I can add the missing part, though... I am new..."