00:01
Okay, if we want to know which of these is a function, then we need to figure out which one passes the vertical line test.
00:08
And the vertical line test says that if i draw a vertical line anywhere on that graph, that i can intersect at most one point.
00:19
So i'm going to use a green highlighter here.
00:22
So the first graph is a cubic graph.
00:25
So no matter where i draw my vertical line, i'm only going through one point.
00:32
Maybe a highlighter is not my best option here, so let me go with something else.
00:39
Now it may look like i'm intersecting more than one point up here at the ends, but i do not.
00:48
It's still going to the right and going up.
00:52
Okay, number two is a square root graph.
00:55
No matter where i put that vertical line, it's going to cross through once.
00:59
Three is a cube root graph.
01:01
Same, it passes the vertical line test no matter where i put that line.
01:07
Four is an absolute value graph.
01:10
It also passes the vertical line test...