Question Number 93367 by Rio Michael last updated on 12/May/20
$$\mathrm{show}\:\mathrm{using}\:\mathrm{demoives}\:\mathrm{theorem}\:\mathrm{that}\: \\ $$$$\mathrm{sin}^{\mathrm{2}} \theta\:\mathrm{cos}^{\mathrm{2}} \mathrm{4}\theta\:=\frac{\mathrm{1}}{\mathrm{8}}\left(\mathrm{1}−\mathrm{cos4}\theta\right) \\ $$
Commented by prakash jain last updated on 14/May/20
$$\mathrm{Please}\:\mathrm{recheck}\:\mathrm{question}. \\ $$$$\mathrm{put}\:\theta=\pi/\mathrm{2} \\ $$$$\mathrm{LHS}\neq\mathrm{RHS} \\ $$
Commented by Rio Michael last updated on 14/May/20
$$\mathrm{thank}\:\mathrm{you}\:\mathrm{sir} \\ $$