Question

Let X = {1, 2, 3, 4}, Y = {1, 2, ..., 10} and f :X → Y be defined by

f(x) = 2x + 1, x Є X. Then the range of f is

• A. {3, 5, 7, 9}
• B. {1, 2, 3, 4}
• C. {1, 2,...., 10}
• D. {5, 6, 7, 8, 9, 10}

Answer 1

The correct option is A

{3, 5, 7, 9}

If f is a function from A to B and (a, b) Є f, then f(a) = b,where b is called the image of a under f. The range of the function is the set of images.

Hence, range is {3, 5, 7, 9}