Question Number 95531 by Abdulrahman last updated on 25/May/20
$$\frac{\mathrm{tanx}×\mathrm{ctg2x}}{\mathrm{tan}^{\mathrm{2}} \mathrm{x}−\mathrm{1}}=? \\ $$
Commented by PRITHWISH SEN 2 last updated on 25/May/20
$$\mathrm{put}\:\mathrm{cot2x}\:=\:\frac{\mathrm{1}−\mathrm{tan}\:^{\mathrm{2}} \mathrm{x}}{\mathrm{2tan}\:\mathrm{x}} \\ $$
Commented by Abdulrahman last updated on 25/May/20
$$\mathrm{then}? \\ $$$$\mathrm{please}\:\mathrm{solve}\:\mathrm{it} \\ $$
Commented by Tony Lin last updated on 25/May/20
$$\frac{{tanxcot}\mathrm{2}{x}}{{tan}^{\mathrm{2}} {x}−\mathrm{1}} \\ $$$$=\frac{{tanx}\frac{\mathrm{1}−{tan}^{\mathrm{2}} {x}}{\mathrm{2}{tanx}}}{{tan}^{\mathrm{2}} {x}−\mathrm{1}} \\ $$$$=−\frac{\mathrm{1}}{\mathrm{2}} \\ $$
Commented by PRITHWISH SEN 2 last updated on 25/May/20
$$\mathrm{Are}\:\mathrm{you}\:\mathrm{a}\:\mathrm{boy}\:\mathrm{or}\:\mathrm{an}\:\mathrm{adult}\:? \\ $$