Answer
$1$
Work Step by Step
We know that
$\sec x=\dfrac{1}{\cos (x)}$
So, we can write this as:
$\cos^2 (x)=\dfrac{1}{\sec^2 x}$
Apply the trigonometric identity:
$\sin^2{x}+\cos^2{x}=1$.
Therefore,
$\dfrac{1}{\sec^2{x}}+\sin^2{x}=\cos^2{x}+\sin^2{x}=1$
