Answer :

It's [tex]sin(40+20)=sin60=\frac{\sqrt3}2[/tex]
PSN03

Yo sup??

The given expression is in the form

sinAcosB+cosAsinB

we know that

sin(A+B)=sinAcosB+cosAsinB

therefore

sin40cos20+cos40sin20=sin(40+20)

=sin60

=√3/2

Hope this helps.