Relations and Functions · Class 12 · CBSE · Science Mathematics
Let f: R → R be defined by f(x) = x². Which of the following describes f?
Practice question from Relations and Functions (Class 12 · CBSE · Science Mathematics), with the correct answer and a step-by-step solution.
easy · MCQ · Q-8DC1C2
Let f: R → R be defined by f(x) = x². Which of the following describes f?
- A.It is both one-one and onto.
- B.It is one-one but not onto.
- C.It is neither one-one nor onto.Correct answer
- D.It is onto but not one-one.
Solution
Since f(1) = f(-1) = 1, f is not one-one. Its range is [0, ∞), which is not all of R, so it is not onto.
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