Consider the function y = 2cos (-x) - 4. What effect does "-x" have on the basic graph?

A) Flip over the vertical axis

B) Horizontal shift left 1

C) Vertical shift down 1

D) Flip over horizontal axis

A)

But really there is no effect since cos (-x) = cos (x).

Step-by-step explanation:

Cosine is an even function.

Even functions are symmetric about the y-axis.

So really for cosine; cos (-x) has no change to cos (x) since they are equal.

But if you keep in mind that cosine is symmetric about the y-axis, then it has been reflected over the y-axis; this is the vertical axis.

A)