Question

Eliminate $\theta$ and find a relation in x, y, a and b for the following questions.

$x=\sec \theta +\tan \theta$
$y=\sec \theta -\tan \theta$

• A. $x+y=0$
• B. $xy=1$
• C. $\frac{x}{y}=1$
• D. $x-y=0$

Answer 1

Answer: (B)

$xy=1$

$xy=({\sec }^2\theta +\tan \theta )(\sec \theta =\tan \theta )$

$xy={\sec }^2\theta -{\tan }^2\theta =1$

$\therefore$ option 'B' is correct.