Question Number 85313 by john santu last updated on 20/Mar/20
$$\mathrm{tan}\:^{\mathrm{2}} \left(\mathrm{20}^{\mathrm{o}} \right)\:+\:\mathrm{tan}\:^{\mathrm{2}} \left(\mathrm{40}^{\mathrm{o}} \right)+\:\mathrm{tan}\:^{\mathrm{2}} \left(\mathrm{80}^{\mathrm{o}} \right)\:= \\ $$
Answered by john santu last updated on 20/Mar/20