If the terminal side of an angle oftradians in standard position passes through the point (6,-8) then cost= ___

If the terminal side of an angle oftradians in standard position passes through the point (-2,3) then tant= ___

If the terminal side of an angle oftradians in standard position passes through the point (1.2,3.5) then sint= ___

Answers would be nice, but explanation is key here! Test tomorrow and i don't understand this at all. Thanks in advance!