Sine Graph Help: Calculating Uoutput & Drawing Graph

[the_man]

Homework Statement

TASK

So I have this task with opamp and I have Uinput Sine Graph, now I have to calculate Uoutput and write it as sine function and draw the sine graph. I know that this is an inverting OPAMP which means that output signal will be inverted, so I just have to flip this Input signal, right? With input signal the horizontal shift is -60° and when I invert the signal it will be +120°, right? This is the problem, I know how to calculate everything, but I am not sure about horzontal shift of output signal, because my friend is keep telling me its -60, and also more important Google is telling that

Now my solution is Uout = 1.43*sin(104,7*10^3*t + 120)

https://www.google.hr/#q=1.43*sin(0.53*t+-+60)
https://www.google.hr/#q=1.43*sin(0.5*t+++120)

Homework Equations

Are google and my friend wrong? Or am I wrong?

The Attempt at a Solution

My Solution

 

[NascentOxygen]

1.43*sin(104,7*10^3*t + 120)

You think this is the answer, so why don't you plot this on graph paper and see whether it resembles the input inverted?

 

[the_man]

I think I am right. Take a look at google link for where solution is +120°. Why is google moving that graaph 120°? It should be moved 120° left of y-axis, right?