f : R → R defined by f(x) = 3 – 4x

Question

In each of the follow cases, state whether the function is one one, onto or bijective.

f : R → R defined by f(x) = 3 – 4x

Answer 1

Let x₁ , x₂ ∈ R 

f (x₁) = f (x₂) ⇒ 3- 4x₁, = 3- 4x₂ 

⇒ x₁ = x₂ hence one-one function

hence f is not onto