Question Number 211456 by BaliramKumar last updated on 09/Sep/24
Answered by A5T last updated on 09/Sep/24
$${max}\:{when}\:\mathrm{8}{cos}\theta−\mathrm{8}{sin}\theta{cos}\theta=\mathrm{0} \\ $$$$\Rightarrow{cos}\theta=\mathrm{0}\:{or}\:{sin}\theta=\mathrm{1}\Rightarrow{max}=\mathrm{8}×\mathrm{1}−\mathrm{4}×\mathrm{1}=\mathrm{4} \\ $$
Answered by mehdee1342 last updated on 09/Sep/24
$${A}=−\mathrm{4}\left({sin}\theta−\mathrm{1}\right)^{\mathrm{2}} +\mathrm{4} \\ $$$${if}\:\:\:{sin}\theta=\mathrm{1}\Rightarrow{maxA}=\mathrm{4}\:\checkmark \\ $$$$ \\ $$