Question

$\Delta ABC$ is right angled at A, the value of $\tan B\times \tan C$ is-

• A. $1$
  
• B. Zero
  
• C. $\tan B$
  
• D. $\tan C$

Answer 1

The correct option is A $1$

In $\Delta ABC$,

$\tan B=\frac{AC}{AB}$ and $\tan C=\frac{AB}{AC}$

$\Rightarrow \tan B\times \tan C=\frac{AC}{AB}\times \frac{AB}{AC}$

$\Rightarrow \tan B\times \tan C=1$