Answer: 1.25
Step-by-step explanation:
The explicit formula for the sequence is 
Substituting in n=4,

Rational ! the number doesn't repeat forever or anything like that. it simplifies nicely.
Answer:




Solving for
we got
and replacing this we got:



And then the best option for this case would be:
b.csc x
Step-by-step explanation:
For this case we have the following expression given:

We know from math properties that the definition for cot is 
If we use this definition we got:


Now we can use the following identity:

Solving for
we got
and replacing this we got:



And then the best option for this case would be:
b.csc x
Answer:
c
Step-by-step explanation:
i just used a calculator lol