Answer
$\dfrac{\pi}{4}$
Work Step by Step
Suppose $\theta = \tan^{-1} (1)$
This gives: $\tan \theta=1$
Now, $\theta = \tan^{-1} (1)=\dfrac{\pi}{4}$
Therefore, $\tan^{-1} (1)=\dfrac{\pi}{4}$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.