Maths Week 1 AQ1.9

[Vineeth Reddy]

I've got a different answer for this question. Can you please explain where I went wrong?

Thank you

[Debajyoti Biswas]

For checking whether bijective, the function is to be injective and surjective. If A=0, f(1)=f(2)=B (for example). Hence this is not injective. Hence not bijective.

Next, for A={-1,1}, f(x) is becoming injective and for every element in the codomain of f, there is at least one element in the domain of f such that f(x) = y. So this is surjective.

[Akshay Malik]

For the function to be surjective, the range must be equal to co-domain which is satisfied only by the second option. And also it is injective.