Here's the question you clicked on:
u0860867
urgent help needed Pls help One last chance left on this question
To start, look at where x = 0. since y equals zero at that point as well, you can eliminate any possible choices which don't equal zero at x = 0. x = 0: y = sin((0) - pi/2) = sin(-pi/2) = -1, not an answer y = -cos(0 - pi/2) = 0, possibility y = cos(0 + pi) = 1, not an answer y = -sin(0) = 0, possibility y = sin(0 + pi) = 0, possibility y = -cos(0) = -1, not an answer
you can then take another point, lets say x = pi/2 to eliminate any other answers 2. y = -cos(pi/2 - pi/2) = -1, possibility 4. y = -sin(pi/2) = -1, possibility 5. y = sin(pi/2 + pi) = sqrt(3)/2, not an answer your answers are 2 and 4