Question

sin150cos120+cos330sin660+1=0

Answer 1

Step-by-step explanation:

sin150 cos120 + cos 330 sin660 +1 = 0

then prove LHS = RHS

L.H.S ,

➡️sin(180°-30°)cos(180°-120°)+ cos (360-30)sin(2x360 - 60) + 1

➡️ sin30°(-cos 60°) + (cos30° ) (-sin60°) +1

➡️ (1/2) .(-1/2) +( root 3/2 )(- root 3/2 ) +1

➡️ (-1/4 )+ (- 3/4)+1

➡️ -4/4 +1

➡️ -1 +1

➡️ 0

so, LHS = RHS proved