Question

If $△ABC$ is right angled at A, then value of $\tan B\times \tan C$ is

• A. $0$
• B. $1$
• C. $-1$
• D. None of the above

Answer 1

The correct option is B $1$

According to the figure

$tanB=\frac{AC}{AB}$

$tanC=\frac{AB}{AC}$

$tanB\times tanC=\frac{AC}{AB}\times \frac{AB}{AC}=1$