Question

cos570×sin510-sin330×cos390​

Answer 1

Answer:

cos570=cos210 { 570/360=210}

cos(270-60)= sin60 ...1

sin510=sin 140 {510/360=140}

sin140= sin180-40= sin 40 .........2

sin330= sin 360-30= sin 30......3

cos 390= cos 360+30= cos 30.....4

from 1,2,3,4

sin60.sin40 -sin30cos30