Answer:
A = 2.6-3.4b
Step-by-step explanation:
I can not see your choices but I'm assuming that this equation is what you are looking for: 16t+vt+ho. The other equation 4.9t+vt+ho is used for meters. I apologize if those weren't your choices as once again I can not see them.
Try to start by reading the manual it came with. If it didn't come with a manual, then your teacher in school will teach you how to use it for specific commands. Otherwise it's just like using a regular calculator but with the ability to do more things, what do you need to know on it?
The answer:
First: sec(-pi) is sec(pi)
And sec(pi) is -1