Kelvin foo's answer to Brianna Jungra's Junior College 2 H3 Maths question.

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Kelvin foo
Kelvin Foo's answer
97 answers (A Helpful Person)
1st
A function needs to pass the vertical line test: meaning any vertical line passes the graph only once. In this case, if you draw a vertical line before the turning point, it cuts the graph at two points. Hence, it is not a function.