3√6cis(π/8) and 2√5cis(7π/6)
assuming only the 5 sand 5 are under the square root
[3√6cis(π/8)]∗[2√5cis(7π/6)]=6√30∗cis(π/8)]∗cis(7π/6)]=6√30∗cis(π/8)]∗cis(7π/6)]=6√30∗e(π/8)i∗e(7π/6)i=6√30∗e((1/8)+(7/6))πi=6√30∗e((3/24)+(28/24))πi=6√30∗e(31/24)πi=6√30∗cis(31π/24)
I have not checked it. That is your job
LaTex
[3\sqrt6 cis(π/8) ]*[ 2\sqrt5 cis(7π/6)]\\
=6\sqrt{30}*cis(π/8) ]* cis(7π/6)]\\
=6\sqrt{30}*cis(π/8) ]* cis(7π/6)]\\
=6\sqrt{30}*e^{(\pi/8)i}*e^{(7\pi/6)i}\\
=6\sqrt{30}*e^{((1/8)+(7/6))\pi i}\\
=6\sqrt{30}*e^{((3/24)+(28/24))\pi i}\\
=6\sqrt{30}*e^{(31/24)\pi i}\\
=6\sqrt{30}*cis{(31\pi/24)}\\