Since sin 60° = √3/2 = cos 30°

and sin 30° = 1/2 = cos 60°

∴ sin 60° cos 30° + cos 60° sin 30° = (√3/2)( √3/2) + (1/2)(1/2)

= (3/4) + (1/4)

= 4/4

= 1