Question

Write the value of $4{\tan }^2\theta -\frac{4}{{\cos }^2\theta }$.

Answer 1

$$\begin{gathered} 4{\tan }^2\theta -\frac{4}{{\cos }^2\theta } \\ =4{\tan }^2\theta -4{\sec }^2\theta \\ =4\left({\tan }^2\theta -{\sec }^2\theta \right) \\ =4\left(-1\right) \\ =-4 \end{gathered}$$