Verify This identitiy: sin(x + y + z) = sinxcosycosz +....

[Timcago]

sin(x + y + z) = sin(x)cos(y)cos(z) + cos(x)sin(y)cos(z) + cos(x)cos(y)sin(z) - sin(x)sin(y)sin(z)

This is insane! :shock:

I dont even know which side i should try to turn into the other.

Please help.

 

[pka]

sin(x+y+z)=sin(x+y)cos(z)+cos(x+y)sin(z)=[sin(x)cos(y)+cos(x)sin(y)]cos(z)+cos(x+y)sin(z).
Now you finish it.