Click insert/object /”Microsoft Formula 3.0 to open the formula toolbar.
Input according to the formula: p = e (y = 1/x
Select the second subscript template in the first line of the third "subscript and superscript" template in the second line of the formula toolbar, and enter the letter I. Note that you need to press the cursor key to the right after entering the subscript I, and the subsequent input will be as big as the previous X!
Input of alpha: Select the second "Greek lowercase letter" template from the right in the first line of the formula toolbar, and enter alpha.
Fraction input: select the second fraction and radical template in the second line of the formula toolbar, input the numerator first, then click the down cursor key, and then input the denominator.
σ input: select the fourth template in the second row of the formula toolbar and the third template in the first row of the summation template. First, enter the following contents according to the method in 2.3, and then click the small squares above and below the σ symbol to enter the upper and lower limits respectively.
I attach an attachment to you, which is a recorded formula. I hope it helps you.