Question

For \(f(x)=x^2+x\), if \(y=1\), which two domain elements have the same image?

Options

• \(1\) and \(0\)

• \(1\) and \(-2\)

• \(2\) and \(-1\)

• \(0\) and \(-1\)

Answer 1

The equation \(x=-y-1\) gives \(x=-2\) when \(y=1\). Thus, the two different inputs \(1\) and \(-2\) have the same image under \(f(x)=x^2+x\).