Tolong bantu, Jika tan teta = -5/3 untuk 279°

Tan t^2 + 1 = sec^2 t
25/9 + 1 = 1/cos^2 t
34/9=1/cos^2 t
cos t= 3/34 √34

cos^2 t + sin^2 t = 1
9/34 + sin^2 t = 1
sin^2 t = 25/9
sin t = 5/3.