this post was submitted on 24 Jan 2024
279 points (100.0% liked)
196
16503 readers
2666 users here now
Be sure to follow the rule before you head out.
Rule: You must post before you leave.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
I'm not a math guru but there are only 4 shapes in this and there are 5 functions? You can describe a circle with a single function. Someone explain?
Well, you can describe a circle with a single function if you look at a function R -> R^2. But a circle can't be the graph of a single function.
f and g form the top an bottom of the circle. note that they only differ by a single sign
you need two of them because a circle can't be expressed by a single function of x as it needs to map every x value to 0 to 2 y values
A graph is just a series of correlated points, a formula to tell you that when x is set to a certain value y has a different value. It follows then that no single function can define a circle because for every given value of x there would have to be two potential values of y.