Question

Which of the following is the perfect relation between $\sec \theta$ and $\tan \theta$ for any value of $\theta$?

• A. ${\tan }^2\theta +{\sec }^2\theta =1$
• B. ${\sec }^2\theta +1={\tan }^2\theta$
• C. ${\tan }^2\theta +1={\sec }^2\theta$
• D. None of these

Answer 1

The correct option is C

${\tan }^2\theta +1={\sec }^2\theta$

The trigonometric identity between $\sec \theta$ and $\tan \theta$ is ${\tan }^2\theta +1={\sec }^2\theta$.