Question Number 136284 by liberty last updated on 20/Mar/21
$${What}\:{is}\:{shortest}\:{distance}\: \\ $$$${from}\:{A}\left(\mathrm{3},\mathrm{8}\right)\:{to}\:{the}\:{circle}\: \\ $$$${x}^{\mathrm{2}} +{y}^{\mathrm{2}} +\mathrm{4}{x}−\mathrm{6}{y}\:=\:\mathrm{12}\: \\ $$
Answered by EDWIN88 last updated on 20/Mar/21
$$\mathrm{Center}\:\mathrm{point}\:\mathrm{the}\:\mathrm{circle}\:\mathrm{is}\:\left(−\mathrm{2},\mathrm{3}\right) \\ $$$$\mathrm{distance}\:\mathrm{from}\:\mathrm{A}\:\mathrm{to}\:\mathrm{center}\:\mathrm{point}\:\mathrm{is}\:\sqrt{\mathrm{5}^{\mathrm{2}} +\mathrm{5}^{\mathrm{2}} }\:=\mathrm{5}\sqrt{\mathrm{2}} \\ $$$$\mathrm{radius}\:\mathrm{of}\:\mathrm{circle}\:\mathrm{r}\:=\sqrt{\mathrm{4}+\mathrm{9}+\mathrm{12}}\:=\:\mathrm{5} \\ $$$$\mathrm{so}\:\mathrm{the}\:\mathrm{shortest}\:\mathrm{distance}\:\mathrm{from}\:\mathrm{A}\:\mathrm{to}\:\mathrm{the}\:\mathrm{circle} \\ $$$$\mathrm{is}\:\mathrm{5}\sqrt{\mathrm{2}}\:−\mathrm{5}\: \\ $$
Commented by EDWIN88 last updated on 20/Mar/21
Commented by greg_ed last updated on 20/Mar/21
$$\boldsymbol{\mathrm{obviously}}\:!\: \\ $$