(a) The function f is injective.

(b) The function f is surjective.

(c) f^-1({0}) = {0}

(d) -1 ∈ f(R)

2. Let f : R2 -> R2 be a function given by f(x1; x2) = (3; x1 - 2*x2)

(a) The function f is injective

(b) The function f is surjective

(c) The image of f is the line dened by y1 - 2*y2 = 3

(d) f^-1({(y1; y2) ∈ R2 , y2 = 0}) is the line dened by x1 - 2*x2 = 0.

Please help! I don't get it at all....