小编注：哇咔咔，同学们，高中数学还记得多少？被函数（function）折磨得死去活来的日子还有印象嘛？其实一早就可以用跳舞的方法来学函数喔~于是上面这些人物造型图，有没有让你回忆起三角函数（trigonometric function）、二次函数（quadratic function）、幂函数（power function）、圆方程等等的函数图象（graph）？

下面来看国外网友对这张图示的评论吧：

The third to last panel is an imaginary number.Shouldn't it be -SQRT(x)?
倒数第三张图是错的吧？难道不应该是-√x 嘛？（根号中的数字不能为负值）

Only for x > 0. For x < 0 it is real.
这里X取小于零的数值就可以成立了

-SQRT(x) would be SQRT(x) flipped over the x axis.
-√x的函数图像与√x的函数图象是关于Y轴对称的。

He should have put sqrt(x2) - would have been a lot easier and could have formed a C!
应该把√x² 的图象放上去，那就是一个对称的C形！

sqrt(x2 ) would be just like the absolute value. You want ±sqrt(x).
楼上的你说错了，C形的话应该是±√x的图象。

Actually it doesn't matter if x is >0 or <0 because the number gets squared and then the - is applied.
X大于零小于零都木有关系啦，总之都已经平方了，然后又加了负号。

The number is not squared.
哪里有平方啊……

You're right. What was I thinking? Forget everything I said.
呃，你说得对，瞧我，脑子秀逗了一下，算了别管我刚才瞎扯的那些。

Slightly relevant occurrence: I opened this while watching Carnivale, and a character said "it's a sin" right as I looked at the first one. Weird.
话说我正一边看Carnivale一边打开这个，刚看到sin(x)，节目里的一个角色就说了一句it's a sin. 好巧！

Yeah but sin(x) is pronounced like "sign"
楼上的，其实这里的sin发音是类似于“sign”的。