Задача 52729 ...

sova

2020-06-27 14:16:29

★

dx=-3sintdt
dy=2costdt

= ∫ ^(π)_(0)((3cost*2sint-3)*(-3sint)+(2sint*3cost+2)*(2cost))dt=

= ∫ ^(π)_(0)(-18sin^2tcost+9sint+12sint*cos^2t+4cost)dt=

=(-18*(sin^3t/3)-9cost-12*(cos^3t/3)+4sint)|^(π)_(0)=

=-9*(cosπ-cos0)-4(cos^3π-cos^30)=

=18+8=[b]26[/b]