Answer
- 1
Work Step by Step
To find exact value of $\tan 135^{\circ}$, let's find its reference angle first. As $ 135^{\circ}$ terminates in quadrant II,
The reference angle = $ 180^{\circ} - 135^{\circ}$ = $45^{\circ}$
As $ 135^{\circ}$ terminates in quadrant II, its $\tan$ will be negative. Therefore by reference angle theorem-
$\tan 135^{\circ}$ = - $\tan45^{\circ}$
= - 1