6√6sin 3π/4 * cos7π/6

[latex]6 \sqrt{6}sin \frac{3 \pi }{4}*cos \frac{7 \pi }{6}= [/latex] [latex]=6 \sqrt{6}sin( \frac{ \pi }{2}+ \frac{ \pi }{4} )*cos( \pi + \frac{ \pi }{6} )= [/latex] [latex]=6 \sqrt{6}cos \frac{ \pi }{4}(-cos \frac{ \pi }{6} )= [/latex] [latex]=-6 \sqrt{6}* \frac{ \sqrt{2} }{2} *\frac{ \sqrt{3} }{2}=-9.[/latex]