Answer
Undefined
Work Step by Step
The trigonometric ratios are as follows: $\sin \theta= \dfrac{opposite}{hypotenuse}$ ; $\cos \theta= \dfrac{Adjacent}{hypotenuse}$ and $\tan \theta= \dfrac{Opposite}{Adjacent}$
Now, $\sec \theta= \dfrac{1}{\cos \theta}=\dfrac{1}{\dfrac{Adjacent}{hypotenuse}}$
So, our required answer is: $\sec \theta=\dfrac{1}{0}$= Undefined
