Semicircles are functions. Consider a circle with the equation x2 + y2 = r2. ... A semicircle is found by taking either the positive or negative statement: Figure 2 - Two semicircles combine to give a circle.
What type of function is a semicircle?
In mathematics (and more specifically geometry), a semicircle is a one-dimensional locus of points that forms half of a circle. The full arc of a semicircle always measures 180° (equivalently, π radians, or a half-turn). It has only one line of symmetry (reflection symmetry).
Is a circle a function yes or no?
A circle can be described by a relation (which is what we just did: x2+y2=1 is an equation which describes a relation which in turn describes a circle), but this relation is not a function, because the y value is not completely determined by the x value.
