Question Number 39395 by Rio Mike last updated on 06/Jul/18
$${Given}\:{that}\:\theta\:{is}\:{an}\:{obtuse}\: \\ $$$${angle}\:{find}\:{tan}\:\theta\:{if} \\ $$$${cos}\:\theta\:=\frac{\mathrm{3}}{\mathrm{5}} \\ $$$$ \\ $$
Commented by MrW3 last updated on 06/Jul/18
$${the}\:{question}\:{is}\:{not}\:{ok}\:{sir}. \\ $$$${if}\:\theta\:{is}\:{an}\:{obtuse}\:{angle}\:{then}\:\mathrm{cos}\:\theta<\mathrm{0}. \\ $$$$ \\ $$$${let}'{s}\:{assume}\:\mathrm{cos}\:\theta=−\frac{\mathrm{3}}{\mathrm{5}} \\ $$$$\Rightarrow\mathrm{sin}\:\theta=\frac{\mathrm{4}}{\mathrm{5}} \\ $$$$\Rightarrow\mathrm{tan}\:\theta=−\frac{\mathrm{4}}{\mathrm{3}} \\ $$
Commented by Rio Mike last updated on 06/Jul/18
$${i}\:{think}\:{your}\:{right}\:..{thanks} \\ $$