As shown in the figure. In fact, the subject has written part of it correctly. It's just that the normal distribution function is too complicated.

Normal distribution function is a higher function, and its value can only be obtained by looking up a table (computer integration). But we don't need to ask what the maximum probability is, but what the standard deviation of normal distribution is.

So this is a problem of how to get the maximum value of the function from the value of the variable, which should be solved by derivative.

Forget to write the probability density function of standard normal distribution first, as shown in the first line of the figure below:

Finally, it is proved that f(x) (also p {2

As shown in the figure, if you have any questions or don't understand, please ask questions! If you often need to ask such questions, you can pay attention.