Sum & Difference Formulas

Question

Express the following as a function of a single angle.

tan(-34°)+tan(-110°)/1-tan(-34°)tan(-110°)

Answer 1

tanθ is an odd function. So, tan(-θ) = -tanθ.

The given expression can be rewritten as (-tan34° - tan110°) / (1 - tan34°tan110°)

= -(tan34° + tan110°) / (1 - tan34°tan110°) = -tan(34° + 110°) = -tan(144°)