1) cos70° + cos50°= cos(70° + 50°)= cos120°= -1/2
2) cos70° + cos10°= cos(70° + 10°)= cos80°
3) sin48° + sin12°= sin(48° + 12°)= sin60°= √3/2
1) cos70° + cos50°
= cos(70° + 50°)
= cos120°
= -1/2
2) cos70° + cos10°
= cos(70° + 10°)
= cos80°
3) sin48° + sin12°
= sin(48° + 12°)
= sin60°
= √3/2