Question

已知sin76°＝m,试用m表示sin7°,cos7°,tan7°

Answer 1

sin76°=cos14°=m

cos14°=cos2*7°=2(cos7°)^2-1 = 1-2(sin7°)^2

sin7°=√(1-m)/2

cos7°=√(1+m)/2

tan7°=sin7°/cos7°=√(1-m)/(1+m)