# Homework Help: Use standard identities to express

1. Apr 4, 2012

### menco

1. The problem statement, all variables and given/known data
Use standard identities to express sin(x+pi/3) in terms of sin x and cos x

2. Relevant equations

sin(a+b)=sinAcosB+sinBcosA

3. The attempt at a solution

sin(x)cos(pi/3)+sin(pi/3)cos(x)
0.5sinx + 0.8660cosx

I'm just not sure if i need to simplify it even further and hopefully I'm on the right track. Thanks

2. Apr 4, 2012

### rock.freak667

That should be fine. I would just express 0.866 as √3/2 as that is an exact value whilst 0.866 is just an approximation.

3. Apr 4, 2012

### cupcakes

that seems right to me. However I'd keep sin(π/3) as $\frac{\sqrt{3}}{2}$.

Edit: I didn't see rock.freak667's reply.

4. Apr 4, 2012

### menco

thanks for the response :)