diketahui cos A=4/5,sin B=5/13,sudut A lancip dan sudut B tumpul.nilai cos(A-B)

cos A = 4/5
sin A = 3/5

sin B = 5/13
cos B = -12/13

cos (A-B) = sin A.cos B + cos A.sinB
= 3/5 x -12/13 + 4/5 x 5/13
= -36/65 + 20/65
= -16/65

semoga membantu!^^