Question

Cos30 cos 60-sin30 sin60=0

Answer 1

lhs=cos30 cos60-sin30 sin60
√3/2×1/2-1/2×√3/2
√3/4-√3/4
√3-√3/4
0/4
0=rhs proved

Answer 2

$\sqrt{3} \div 2 \times 1 \div 2 -1 \div 2 \sqrt{3} \div 2$
$\sqrt{3} \div 4 - \sqrt{3} \div 4$
$\sqrt{3} - \sqrt{3} \div 4$
$1.2990381057 \: or \: 0$