Answer:
θ = 
(60° )
Step-by-step explanation:
Using the identity
sin²x + cos²x = 1 ⇒ sin²x = 1 - cos²x
Given
cos²θ - sin²θ = 2 - 5cosθ
cos²θ - (1 - cos²θ) = 2 - 5cosθ
cos²θ - 1 + cos²θ = 2 - 5cosθ
2cos²θ - 1 = 2 - 5cosθ ( subtract 2 - 5cosθ from both sides )
2cos²θ + 5cosθ - 3 = 0 ← in standard form
(cosθ + 3)(2cosθ - 1) = 0 ← in factored form
Equate each factor to zero and solve for θ
cosθ + 3 = 0
cosθ = - 3 ← not possible as - 1 ≤ cosθ ≤ 1
2cosθ - 1 = 0
cosθ = 
, so
θ = 
( ) = ( or 60° )
Answer:
idk dude
Step-by-step explanation:
The correct answer would be 2.7 centimeters. Hope this was helpful, and if so, please give Brainliest. (:
Answer:
81.6 inches is the circumference
Step-by-step explanation:
Circumference is π times diameter.
We can use a common value of π, 3.14
3.14 × 26 = 81.64
Round to 81.6 inches
By using the general formula for a geometric sequence, we will find that the correct option is c: 86
<h3>
Working with geometric sequences:</h3>
The general formula for the nth term in a geometric sequence is:
Where r is the common ratio of the geometric sequence here we know that:
- a₁ = 2
- a₇ = 128
- r is negative.
Replacing the first two in the general formula we get:
Where we took the negative solution for the root. Now that we know the common ratio we can find the other terms:
The sum gives:
2 - 4 + 8 - 16 + 32 - 64 + 128 = 86
So the correct option is c.
If you want to learn more about geometric sequences, you can read:
brainly.com/question/9300199
