Chapter 4 - Section 4.7 - Inverse Trigonometric Functions - Exercise Set - Page 626: 38

$380$

Suppose $\theta =\tan^{-1} (380)$ This gives: $\tan \theta=\tan[\tan^{-1} (380)]$ The inverse property states that $\tan(\tan^{-1} a)=a $ satisfies for every real number $ a $ . Therefore, we have $ \tan[\tan^{-1} (380)]=380$