help with further trig question (1 Viewer)

[MysteryMarkWarrior]

Hey how would this question be solved?

sin(A + B - C) cos(A - B + C) + cos (A + B - C) sin(A - B + C)

 

[fan96]

Use the angle sum identity:

 

[Ted_]

sin(a + b) = sin(a)cos(b) + cos(b)sin(a)

Similarly:

sin(A + B - C)cos(A - B + C) + cos(A + B - C)sin(A - B + C) = sin[(A + B - C)+(A - B + C)]
= sin(2A)

Here's the answer, little late sorry