Question
Find the value of the following trigonometric ratio :
\[ \tan \frac{7\pi}{4} \]
Solution
\[ \tan \frac{7\pi}{4} = \tan\left(2\pi-\frac{\pi}{4}\right) \]
Using,
\[ \tan(2\pi-\theta)=-\tan\theta \]
\[ = -\tan\frac{\pi}{4} \]
\[ = -1 \]
Answer :
\[ \boxed{ \tan\frac{7\pi}{4}=-1 } \]