<u>Answer:</u>
The correct answer option is:
.
<u>Step-by-step explanation:</u>
We know that the
term
for an arithmetic sequence is given by:

where
is the number of the position of the term.
We are supposed to find the first four terms of the sequence so we will substitute the values of
from 1 to 4 in the given formula to get:
1st term:

2nd term:

3rd term:

4th term:

A.)

Use the identities

and

on the left-hand side

Make 1 have a common denominator to allow for fraction subtraction
Multiply the numerator and denominator of 1 by cos^2 x

Use Pythagorean identity for the numerator.
If

then subtracting both sides by

yields

. We can substitute that into the numerator

======
b.)

For the left-hand side:
By definition,

and

Since

Using Pythagorean identity,

so
Answer:
a₄ = 1.25
Step-by-step explanation:
Given that,
First term of GP, a₁ = 10
The common ration of GP, r = 0.5
The nth term of the GP is given by :

So, the fourth term of the GP is 1.25.
It would seem that r correlates to line AC. So another name could be Line AC. Remember to put a line above the two letters to let people know it is a line. I hope this helps! =)
I think you would divide 91 by 35% which is 260 students.