Differentials - not understanding directions

[lp27]

Homework Statement

Find dy and evaluate dy for the given value x and dx
.

y = x^3 - 3x, x = 2, dx = 0.05

Homework Equations

The Attempt at a Solution

I have no idea how to begin this problem.
I assumed that I find y'.
Then plug in x into y'.
Following that, I am not sure.

 

[diazona]

\mathrm{d}y = \frac{\mathrm{d}y}{\mathrm{d}x}\mathrm{d}x = y'\,\mathrm{d}x

 

[lp27]

Thank you, that was straight forward.