Answer:
see explanation
Step-by-step explanation:
Using the double angle identity for sine
sin2x = 2sinxcosx
Consider left side
cos20°cos40°cos80°
= 
(2sin20°cos20°)cos40°cos80°
= 
(2sin40°cos40°)cos80°
= (sin80°cos80° )
= 
(2sin80°cos80° )
= . sin160°
= . sin(180 - 20)°
= . sin20°
= 
= right side , thus proven
So to solve problems like these you can work out each equation by substituting the x and y with the coords from the vertex (2,-4) and which ever one is true is the corresponding equation.
Lets try the first one
A) y = 2( x-2)^2-4 this would become
-4 = 2(2-2)^2-4 we solve this and get
-4 = 2(0)-4
-4 = -4
so it seems like A is the correct answer, of course we'd wanna check out the other answers just to be sure.
Lets try one and do C
C) -2 = 2(-4-2)^2+2
-2 = 2(-8)^2+2
-2 = 130
These aren't equal so this can't be our equation
So you can also do one more just to be super sure you have the right answer but I think A is the correct one :)
Answer: The number is 12
Step-by-step explanation:
n=number
2n-8=16
2n=24
n=12
The degenerate conic that is formed when a double cone is sliced at the ap-ex by a plane parallel to the base of the cone is a <u>Point</u>.
<h3>What degenerate conic is formed?</h3>
When a plane that is parallel to the base of a double cone is used to slice the ap-ex, the conic section formed is a circle.
Circles lead to a Point degenerate conic being formed because a single point will be formed on the double cone that separates the shape.
Find out more on degenerate conics at brainly.com/question/14276568
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