So 4 factorial divided by 0 factorial times 4 factorial.

So this is equal to 4 factorial over 0 factorial times 4 factorial, right 4 minus 0 is 4 a to the fourth plus 4 factorial over 1 factorial times 3 factorial, right?

That's 4 factorial over 2 factorial times 2 factorial, right?

That's plus 4 factorial over 4 factorial times 0 factorial b to the fourth.

It's 2K pi times sigma.

That's 4 factorial over 3 factorial.

That equals n factorial over 1 factorial divided by n minus 1 factorial times x to the n minus 1.

Because, if we all understand that animals use their eyes to see, ears to hear, noses to smell, mouths to eat,

So that's 4 factorial over 1 factorial, which is also 1, divided by 4 minus 1 factorial.

10 factorial divided by 9 factorial that's 10.

So n factorial divided by n minus 1 factorial, that's just equal to n.

And the strength of the field, or the magnitude of the field, is equal to 2 times Coulomb's constant times pi times the charge density of the plate.

3 factorial over and then 3 minus 2 factorial.

4 minus 3 is 1 factorial. ab cubed.

We could write it as n factorial it s a lower case n n factorial over n minus k factorial.

So 1 times c1 times 1 is equal to 1.

So that's the number of unique combinations, where you have four out of six heads, times the probability of each of the combinations, which is 1 2 to the sixth power.

That's 26 factorial.

4 factorial.

Times this guy over here. v2 dot v2 minus v2 dot v1 squared over v1 dot v1.

So I'll write that down. e to the 0 is 1 times c1 times cosine of 0, plus c2 times sine of 0.

Minus 2 times e to the 0, times cosine of 0, that's 1, plus c2 times sine of 0.

That's just 1 times itself plus 0 times everything else.

This means 10 factorial over 2 factorial times 10 minus 2 factorial.

It's lambda 1 times v1 plus 0 times v2 plus 0 times v3, all the way to 0 times vn.

If I have 7 factorial divided by 6 factorial, that's just 1.

And then the numerator is the factorial of my exponent.

So now 4 times 3 factorial, that's just 4 factorial over s to the fifth.

V2 dot v1, that's going to be and we're going to multiply the numerator times itself, v2 dot v1.

Times v1 dot v1.

This is just times dx.

So you get 4 factorial over factorial.

That's 7 factorial.

1 factorial is 1.

So it's a times n.

Times minus sine of 0.

Over what's 2 factorial?

So v2 dot v1 squared, all of that over just one of these guys. v1 dot v1.

You shouldn't just memorize it. n choose k from our combinatorics is equal to n factorial over k factorial divided by n minus k factorial.

But we only took the first 3 of the factorial.

To write the first k of n factorial.

The 3 largest components of 7 factorial.

So a times n is 1.

That's 98 times this quantity over here, downwards

And we're going to divide by 6 factorial.