Trigonometric Equations Question 367

Question: If the median of $ \Delta ABC $ through A is perpendicular to $ AB $ , then

Options:

A) $ \tan A+\tan B=0 $

B) $ 2\tan A+\tan B=0 $

C) $ \tan A+2\tan B=0 $

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

  • We have $ BD=DC $ and $ \angle DAB=90^{o} $ . Draw CN perpendicular to BA produced, then in $ \Delta BCN $ , we have $ DA=\frac{1}{2}CN $ and $ AB=AN $ Let $ \angle CAN=\alpha $ $ \because \tan A=\tan (\pi -\alpha )=-\tan \alpha $ $ =-\frac{CN}{NA}=-2\frac{AD}{AB}=-2\tan B $
    Þ $ \tan A+2\tan B=0 $ .