Question

$9{\tan }^2\theta -9{\sec }^2\theta =$

• A. $1$
• B. $0$
• C. $9$
• D. $-9$

Answer 1

The correct option is D $-9$

$9ta{n}^2\theta -9se{c}^2\theta =-9(se{c}^2\theta -ta{n}^2\theta )$
$=-9\left(1\right)$
$=-9$
Option D is correct.