Question

Could I have some help with these couple problems?

Which of the following are trigonometric identities?
cos22x + sin22x = 1
sec2x + csc2x = 1
sec2x - tan2x = 1
tan2x - sec2x = 1

Which of the following pairs of coordinates do not represent the same point in polar coordinates?
(r,theta) and (-r,theta)
(r,theta) and (-r,theta+pi )
(r,theta) and (-r,theta +2pi )
(r,theta) and (r,theta +2pi )