Which of the following represent the same graph? Check your result analytically using trigonometric identities. (a) y

Question:

Which of the following represent the same graph? Check your result analytically using trigonometric identities.
(a) y = sin(x + π/2)
(b) y = cos(x + π/2)
(c) y = -sin(x + π)
(d) y = cos (x - π)
(e) y = -sin (π - x)
(f) y = cos (x - π/2)
(g) y = - cos (π - x)
(h) y = sin (x - π/2)