Question

Найти значение выражения 6tga*sin(π-a) если cosa=0.3

Answer 1

tg(a)=sin(a)/cos(a),
sin(pi-a)=sin(a),
sin^2(a)=1-cos^2(a):

6tg(a)×sin(pi-a)=
=6(sin(a)/cos(a))×sin(a)=
=6sin^2(a)/cos(a)=
=6(1-cos^2(a))/cos(a)
↓
6(1-0,3^2)/0,3=
=6(0,91)/0,3=
=20×0,91=

=18,2.