Indefinite integration

[late prism]

I got all options except d but d is also correct. Could someone help me?

[west bough]

1. Wait patiently for a helper to come along.
2. Once someone helps you, say thank you and close the thread with:

+close

3. Feel free to nominate the person for helper of the week in #helper-nominations
4. Do not ping the mods, unless someone is breaking the rules.
5. If you're happy with the help you got here, and the server overall, you can contribute financially as well:

[late prism]

How do I reach from tan-1(tan²x) to option d?

[late prism]

Anyone?

[radiant pewter]

$-tan^{-1}(z)=tan^{-1}(-z)$ but $\ -cos(2x) \leq 1 < 3 = tan^2(\frac{\pi}{3})$ for all x

[pine crown]

Ludwig

[late prism]

what

[radiant pewter]

I showed that (C) and (D) can't be the same.