Question Number 101589 by student work last updated on 03/Jul/20
$$\mathrm{if}\:\mathrm{sin10}^{\mathrm{0}} =\mathrm{x}\:\:\:\:\:\:\:\:\:\:\mathrm{then}\:\:\:\mathrm{sin70}^{\mathrm{0}} =? \\ $$
Answered by Dwaipayan Shikari last updated on 03/Jul/20
$${sin}\mathrm{70}°={cos}\mathrm{20}°=\mathrm{1}−\mathrm{2}{sin}^{\mathrm{2}} \mathrm{10}°=\mathrm{1}−\mathrm{2}{x}^{\mathrm{2}} \\ $$