How to do these calc problems?

Question

1) Comparing Δy and dy, where Δy=f(x+Δx)-f(x) and dy=f'(x)dx

Let f(x)=x^2+x, x=2 and x=dx=0.2

f(x+Δx) =?
I have (2+0.2)^2 + (2+0.2) = 7.04, not sure if right or not

Δy=?

dy=?

Answer 1

The function

x = 2, dx = 0.2

 

are differ by very small ammount.