Which relation is a function?

{(6, 0), (–7, 14), (–2, –5), (–2, 5)}

{(–1, 3), (5, 3), (–6, 7), (9, 0)}

{(0, –7), (4, –8), (0, –9), (4, –10)}

{(2, 4), (2, –7), (2, 11), (2, –15)}

(sin 42)/31. = sinx)/37

sinx = 37 (sin42)/31

= 37× 0.66/31 = 0.787

x= 51.9

other angle opposite to y = 180-51.9-42

= 180- 93.9 =86.1

so

sin42)/31 = sin 86.1)/y

0.021 = 0.997 /y

y= 0.997/0.021 =47.47