c) I assume Dx means Domain of x.
Since x is inside a square root, that means that everything inside the square root has to be greater that or equal to 0.
[tex] x + 3 \geqslant 0 \\ x \geqslant - 3[/tex]
Therefore, Dx is: [-3, infinity)
d) I assume Ry means the range of y.
Since x can only take values greater than or equal to -3, this means that the values of y start when x=-3 (another way of writing this is f(-3) )
[tex]y = \sqrt{ - 3 + 3} + 2 \\ y = 2[/tex]
From there, as x increases, y increases.
Ry= [2, infinity)
I don't know what your teacher asks you in e and f.
