which relation is a function?
which relation is a function?
Answer
Explanation:
Step1: Recall vertical - line test
A relation is a function if any vertical line drawn on its graph intersects the graph at most once.
Step2: Analyze first graph (circle)
A vertical line can intersect a circle at two points. So, it is not a function.
Step3: Analyze second graph (side - ways parabola)
A vertical line can intersect a side - ways parabola at two points. So, it is not a function.
Step4: Analyze third graph (up - opening parabola)
Any vertical line drawn on the graph of an up - opening parabola will intersect it at most once. So, it is a function.
Step5: Analyze fourth graph (vertical line)
A vertical line itself fails the vertical - line test as it intersects at infinitely many points for a single x - value. So, it is not a function.