Is there an expression for electric energy

Is there an expression for electric energy

Of course, the expressions of electric energy in middle school physics electromagnetics mainly include electric work w = uit and Joule's law q = I ^ 2R. There are many electromagnetic energy formulas in general physics electromagnetics. In addition to the above two, the relatively simple ones are capacitance energy formula w = Cu ^ 2 / 2 (C is capacitance) and self induction energy formula w = Li ^ 2 / 2 (L is self induction coefficient)

Li Daoyuan wrote a sentence about the scenery of the Three Gorges in autumn

At the beginning of every clear day and frost day, there are often high apes whistling in the forest. It is a kind of sad and strange thing. The sound of empty valley is heard, and the sorrow turns for a long time!
It should be

Taylor's formula for limit problem
The limit of N tending to infinity Lim [n-n2ln (1 + 1 / N)] is equal to 1 / 2 by Taylor formula, but let x = 1 / n
Then the original formula is equal to N2 (1 / n-ln (1 + 1 / N)) = (x-ln (1 + x)) / X2, which is infinite by using the law of Robita
Why

When x approaches 0, the limit of (x-ln (1 + x)) / x2 = (1-1 / (1 + x)) / 2x = 1 / [2 (1 + x)] = 1 / 2
That's right

The number of male students in a class is four fifths of that of female students, male students account for () of the whole class, female students account for () of the whole class, and female students account for () of the whole class

The number of male students in a class is 4 / 5 of that of female students. Male students account for 4 / 9 of the total class, female students account for 5 / 9 of the total class, and female students account for 5 / 4 of the total class

What is 29 and 7 / 13 divided by minus 6

29 7 / 13 △ (- 6)
＝384/13×（-1/6）
＝-64/13

Finding the limit of (1 + 2 / N) ∧ n

Original formula = (1 + 2 / N) ^ n / 2 * 2
=e^2

Dad has 60 pieces of RMB with a face value of 10 yuan and 5 yuan, a total of 490 yuan. How many of these two kinds of RMB are there? Please don't use the equation

Suppose that the face value is 10 yuan, a total of 60 × 10 = 600 yuan
So the 5 yuan face value is (600-490) / (10-5) = 110 / 5 = 22
60-22 = 38 for 10 yuan
It belongs to the problem of profit and loss

Find the law: (), 3,5,7, (), (), 17

2, 11, 13. Prime

Who can write the prime numbers of the combined numbers within 100?

Prime numbers are 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97
25 in total
There are 74 total numbers (except 1 and prime numbers)

The derivative of y = cos X / (1-sin x)

y'=[-sinx(1-sinx)-cosx(-cosx)/(1-sinx)²=[-sinx+sin²x+cos²x]/(1-sinx)²=1/(1-sinx)