Пожалуйста! 1/pi * arcsin(cos 26pi/5)

Question

Пожалуйста! 1/pi * arcsin(cos 26pi/5)

Answer 1

Ответ:

-0,3

Пошаговое объяснение:

1/π* arcsin(cos 26π/5)=1/π* arcsin(cos (4π+6π/5)=

=1/π* arcsin(cos (6π/5)=

1/π* arcsin(cos (π+π/5)=

=1/π* arcsin(-cos (π/5)=

=1/π* arcsin(-cos (π\2-3π/10))=

=1/π* arcsin(-sin (3π/10))=

=-1/π* 3π/10=-0,3

Answer 2

1) 26π/5=4π+π+π/5=2*2π+π+π/5

2) cos (6π/5)=cos (2*2π+π+π/5)=cos (π+π/5)=-cos (π/5)=-sin(π/2-π/2+π/5)=

-sin(π/2-3π/10)=-sinπ3π/10

3) (1/π*) arcsin(cos 26π/5)=(1/π)* arcsin(sinπ3π/10)=-(3π/10)*(1/π)=-3/10