Question

If it’s half a circle can it be a function

Answer 1

No, a half circle cannot be a function because it fails the vertical line test. In a function, each input value (x) must correspond to exactly one output value (y), meaning that no two different points on the graph of the function can have the same x-coordinate. However, in a half circle, there are multiple y-values for a single x-value, which violates this rule.