Answer:
[tex]-\frac{8\sqrt{2}+2}{15}.[/tex]
Step-by-step explanation:
1) sin(a+b)=sin(a)cos(b)+sin(b)cos(a);
2) if sin(a)=-0.4, then cos(a)=0.8; if cos(b)=1/3, then sin(b)=-√8/3;
3) finally, sin(a+b)=-0.4*1/3-√8/3*0.8=
[tex]=-\frac{8\sqrt{2}+2}{15}.[/tex]
