Find integers a such that x^2 is ≡ a (mod 4) for some integer x

[sturdy pelican]

What does this mean? I am struggling to understand the question

[daring quiver]

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[molten flame]

it wants you to find the quadratic residues mod 4, for this the residues are 1 and 0, up to you to prove that those are the only values of a

[molten flame]

depending on your course 0 might not be counted as an independent residue

[sturdy pelican]

ohhh so just the possible values of a for all x

[molten flame]

exactly

it's fairly simple to prove by exhaustion your quadratic residues

[sturdy pelican]

sweet, thank you @molten flame

[molten flame]

np

[vast trench]

@sturdy pelican has given 1 rep to @molten flame

[sturdy pelican]

+close