Puzzles
Parabola
Source: Alex Through the Looking-Glass: How Life Reflects Numbers and Numbers Reflect Life by Alex Bellos
On a graph of \(y=x^2\), two lines are drawn at \(x=a\) and \(x=-b\) (for \(a,b>0\). The points where these lines intersect the parabola are connected.
![](javascript:showlimage("parabola.png"))
What is the y-coordinate of the point where this line intersects the y-axis?
If you enjoyed this puzzle, check out Sunday Afternoon Maths XVIII,
puzzles about graphs, or a random puzzle.
puzzles about graphs, or a random puzzle.