1.cos3+cos2x2.sin 40°+sin 16°3.sin 46°-sin 74°4.son 12°+sin 20°5.cos 52°- cos 32°

Question

1.cos3+cos2x
2.sin 40°+sin 16°
3.sin 46°-sin 74°
4.son 12°+sin 20°
5.cos 52°- cos 32°

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Answer 1

                                 2
1)cos3+cos2x=cos3x
2)sin46-sin74=sin -28
3)sin 12+sin20=sin32
4)cos52-cos32=cos20