Use a sum or difference identity to find the exact value.
-$$\frac { \tan 155 ^ { \circ } - \tan 35 ^ { \circ } } { 1 + \tan 155 ^ { \circ } \tan 35 ^ { \circ } }$$
A) $- \frac { 1 } { 2 }$
B) $- \frac { \sqrt { 3 } } { 3 }$
C) $- \sqrt { 3 }$
D) $- 2$

Question

Quizplus · Accepted Answer

The expression is equivalent to $\tan(155^\circ - 35^\circ) = \tan(120^\circ)$, which equals $-\sqrt{3}$.

Use a Sum or Difference Identity to Find the Exact tan⁡155∘−tan⁡35∘1+tan⁡155∘tan⁡35∘\frac { \tan 155 ^ { \circ } - \tan 35 ^ { \circ } } { 1 + \tan 155 ^ { \circ } \tan 35 ^ { \circ } }1+tan155∘tan35∘tan155∘−tan35∘​

Use a Sum or Difference Identity to Find the Exact $\frac { \tan 155 ^ { \circ } - \tan 35 ^ { \circ } } { 1 + \tan 155 ^ { \circ } \tan 35 ^ { \circ } }$