Science:Math Exam Resources/Courses/MATH220/April 2011/Question 09 (c)/Solution 1

The example that we constructed in part (b) showed a case where the function f is not surjective and so it cannot be possible for $f\circ g$ to be surjective either. For example, in that case, no negative number is in the image of the function f and so no negative number can be in the image of $f\circ g$ either.