Question

Buktikan cos 60 derajat . cos 30 derajat - sin 60 derajat . 30 derajat =

Answer 1

Cos 60 derajat.cos 30 derajat-sin 60 derajat.sin 30 derajat=
1/2.√3/2-√3/2.1/2=0

Answer 2

Sin 60 = 1/2 √3
sin 30 = 1/2
cos 60 =  1/2
cos 30 = 1/2√3
maka
= (1/2 x 1/2 √3) - (1/2√3 x 1/2)
= √3/4 - √3/4
= 0