Question

a)cos40˚-cos10˚ ,

б)sin42˚-sin26˚,

в)cos37˚+cos23˚,

г)sin130˚+sin110˚ ,

д)cos20˚-cos70˚,

е)sin(α+x)-sinα,

ж)cos(α-β)+cos(α+β),

з)cos50˚-sin70˚,

и)sin20˚-cos20˚

Answer 1

cos40-cos10=cos30= √3/2

sin42-sin26= sin16=0.2756

cos37+cos23=cos60=0.5

sin130+sin110=sin140 0.6428

cos20-cos70=-cos50