Which description matches the transformations y = cos x undergoes to produce y = 2cos(-x) - 4?

Question

anonymous · Answer

the -x part does nothing because cosine is even and so 
$$\cos(-x)=\cos(x)$$

anonymous · Answer

$$2\cos(x)$$ has a amplitude 2, so goes form -2 to 2 instead of from -1 to 1
then -4 at the end moves the whole graph down 4 units, instead of going from -2 to 2 it goes from -6 to -2

anonymous · Answer

A.	Horizontal compression by factor 2, vertical shift by 4 units up, then a reflection across the x-axis
 		B.	Reflection across the y-axis, vertical stretch by factor 2, then a vertical shift down 4 units
 		C.	Reflection across the y-axis, vertical shift of 2 units, horizontal shift right by 4 units
 		D.	Horizontal shift left 1 unit, then vertical shift down by 4 unit

anonymous · Answer

B but that is a very stupid answer

anonymous · Answer

since you cannot see the reflection across the y - axis!

apoorvk · Answer

cosx and cos(-x) are same. becaus edoesnt matter how you turn the angles on the plane, cos takes same values


so
graph:

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