Question

Will mark brainiest for simplest and most coherent answer. What does it mean if an x (input) or y (output) value doesn't make sense? What does it look like on a graph? What happens in the equation?

Answer 1

Answer:

I tried to answer but I still would like to know what doesn't make sense.

Considering the identity:

$\sec^2\theta-\tan^2\theta=1 \implies |\sec\theta|\geq1$

$\forall\;\theta\in\mathbb{R}-\{(2n+1)\frac{\pi}{2}, n\in\mathbb{Z} \}$

The identity is true whenever both sides are defined. It is not supposed to hold the values when we have division by zero, because it is undefined.

If the value doesn't make sense, it is probably not a function, or it is undefined by the given value of $x$.

Let's go back to the definition of function again:

A function relates a set of inputs and a set of allowable outputs where each input is related to only one output. It basically defines the relation of ordered pairs.

Hope it helped you a bit.