T 2 3 4 15 6 9 10 Review the diagram of the unit circle. Based on the diagram, which equation can be simplified to derive the cosine sum identity? y O R (cos(u + v), sin(u + v)) V (cos(u + v)- 1)2 + (sin(u + v)- 0)2 = v(cos(u)-1)2 + (sin(u)-0)2 O Q (cos(u), sin(u)) V (cos(u + v)- 1)2 +(sin(u + v)- 0)2 = v(cos(-V)-1)2 + (sin(-V)-0)? U X O -U P (1, 0) (cos(u + v)- 1)2 + (sin(u + v)-0)2 =(cos(u)-cos(- v)2+ (sin(u)-sin(=v)2 O S (cos(-v), sin(-v)) (cos(u + v) - 1)2 + (sin(u + v)- 0)2 = (cos(u + v)- cos(u))2 +(sin(u+ v)-sin(u))