What is the correct equation for the function whose graph is shown?

a. y = -5 cos 3x
b. y = -3 cos 5x
c. y = 3 cos 5x
d. y = 5 cos 3x

i know its either b or c. but i'm not sure which one relating to the positive/negative 3.

y= 3 cos 5x would be my best educated guess.

given that triangle abc is transformed two times to get triangle

a"b"c"

first abc is transformed in to a'b'c' as follows:

the coordinates of a are (1,-1) and transformed into a'(-1,1)

similarly b (4,-2) became b'(-4,2) and

c(7,-2) became c'(-7,2)

i.e. (x,y) becomes (-x,-y)

this is nothing but reflection about a point here origin.

thus first transformation is reflection on the origin.

next is exactly shifting 3 units down

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