Answer:
- cos(2Ф) = cos²(Ф) -sin²(Ф)
- cos(2Ф) = 1 -2sin²(Ф)
- cos(2Ф) = 2cos²(Ф) -1
Step-by-step explanation:
The angle sum formula for cosine is ...
cos(α+β) = cos(α)cos(β) -sin(α)sin(β)
When we have α = β = Ф, this becomes ...
cos(Ф+Ф) = cos(Ф)cos(Ф) -sin(Ф)sin(Ф)
cos(2Ф) = cos²(Ф) -sin²(Ф)
The "Pythagorean identity" can be used to write this in terms of sine or cosine.
cos(2Ф) = (1 -sin²(Ф)) -sin²(Ф)
cos(2Ф) = 1 -2sin²(Ф)
or
cos(2Ф) = cos²(Ф) -(1 -cos²(Ф))
cos(2Ф) = 2cos²(Ф) -1
<h3>
Answer: 14</h3>
================================
Explanation:
The two angles shown are a linear pair. They are adjacent and supplementary.
Supplementary angles add to 180
(8x+1) + (4x+11) = 180
8x+1+4x+11 = 180
(8x+4x) + (1+11) = 180
12x+12 = 180
12x+12-12 = 180-12 ... subtract 12 from both sides
12x = 168
12x/12 = 168/12 ... divide both sides by 12
x = 14
Hey z shs d 2 , e dndbdjdbdud us ske ux he 4 670.2
Answer:
<h2><u>
All of the above EXCEPT pentagons</u></h2>
Step-by-step explanation:
Well I already explained in the comments and I am pretty sure you already answered the question but for the points :)
Good day!
