[Math] Find the value of: tan(100) + tan(125) + tan(100)•tan(125)

trigonometry

The question given was – solve all the equations that are possible to solve without a calculator. (This is a part of it) Please try to solve this question (obviously without a calculator) if it's possible. 🙂 thanks in advance.

All values are in degrees

Best Answer

Hint: $\tan(\alpha + \beta)=\dfrac{\tan(\alpha)+\tan(\beta)}{1-\tan(\alpha)\tan(\beta)}$ and $\tan(225^\circ)=1$.