Jawabanmu

2014-03-06T17:43:30+07:00
Sudut lancip - kuadran 1 semua +
kuadran 3 - tan dan cot +

sec B = 1/cos B
13/12 = 1/cos B
cos B= 12/13
sin B= 5/13 

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

cosAcosB+sinAsinB=
4/5 12/13+3/5 5/13=
(48+15)/65=
63/65
2 3 2