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逆，指数和对数函数
求函数的逆函数。在这个例子中，我们来看看逆的图形解释。在我身后，我有一个函数，它被定义为两个点，让我们的生活简单一点。好吗?
我要做的是画出这些点。我们有点(2,4)2、4。还有点(- 1,3)好的。这是大致的点。现在我要做的是求逆。好吧?记住，只要求出逆函数只要把x和y的值交换一下。所以我们的逆矩阵包含点(4,2)和点(3，- 1) Okay? Plotting those as well. We now go over 4 up 2 and over 3 down 1. And basically what happens whenever we plot the inverses is we reflect everything over this line y=x, okay? So what that looks like is if you'd sketch in the line y=x, [IB] just the slip of 1 through the origin. Every point is gets reflected or [IB] over that. So this point here just gets flipped over to that. this point here flipped over to that. The easiest way for me to sort of draw these out is to draw perpendicular lines. If you just wanted to find this without finding the actual point, draw perpendicular lines and the distance l is going to be roughly the same distance to that point. Okay? So just draw a perpendicular segment, flip it over and that point should end up reflected over the line y=x.
通过翻转直线y=x求出逆函数的图像。
