What is a one-to-one function, and how can you determine if a given function is one-to-one?, questions help

Please answer the following 3 questions in depth:1. What is a one-to-one function, and how can you determine if a given function is one-to-one? Provide complete details and answer in a complete sentence.2. True or false (justify your decision):The graph of f(x) = (x + 2) + 6 is the graph of f(x) = x shifted 2 units right and 6 units up.3. True or false (justify your decision): A rational function may, or may not, have a horizontal asymptote, but it will always have a vertical asymptote.