Answer:
419x573=240,087 ears of corn
Step-by-step explanation:
By using the rules:

We have proven the identity. Below you can follow the demonstration.
<h3>
</h3><h3>
How to prove the identity?</h3>
Here you need to remember two things:

Here we have the expression:

By using the first rule, we can rewrite:

By using the second rule, we can rewrite:

Now if we multiply and divide by cos(x), we get:

In this way, the identity was proven.
If you want to learn more about trigonometric identities:
brainly.com/question/7331447
#SPJ1