I have to verify these identities: sin(x + y + z) = ...

[Fullmetal_Hye]

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)

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

Also, I have to graph y = sin(x)cos(x), and I do not know how. I need help here!!

Thank you!

 

[pka]

Look at the reply at:
http://www.freemathhelp.com/forum/viewtopic.php?t=15594

 

[Fullmetal_Hye]

Thank you!

Thank you; I got it

But can anyone tell me how to graph y = sin(x)co(x)? I guess the problem is really easy but I just forgot how. The teacher said rewrite the expression so that it looks like something you can graph...?

Thank you.

 

[pka]

\(\displaystyle \L
\sin (x)\cos (x) = \frac{{\sin (2x)}}{2}\)