Question

What trigonometric function represents the graph?

f(x) = −2 cos(x − pi over 2)

f(x) = −2 sin(x − pi over 2)

f(x) = 2 cos(x − pi over 2)

f(x) = 2 sin(x − pi over 2)

Answer 1

where's the weird graph? ; )

Answer 2

It's a cosine graph, first of all. Then because it goes up to 2 (it has an amplitude of 2, that is) its "2cos..." Because it starts in the positive y values, it's not a -2cos graph, it's a "2 cos..." graph. So your answer is the third choice down.