Question

If cos (40+x)= sin 30 find x

Answer 1

sin30°=1/2=cos60°
cos60° can be written as cos(40+x)
therefore x=20°

Answer 2

Hey!



sin  30° = sin(90°- 60°) = cos 60°
cos(40°+x) = sin 30°
⇒cos(40°+x) = cos 60°
⇒40°+x = 60°
⇒x= 20