Math Is Fun Forum

This setup

2A = (1+e^B)e^C + (1+e^(-B))e^(-C)

is similar to drift-diffusion in a transistor .

We couldn't get it into closed form unless we made some assumptions.

is there anything special about

C1, MD/H and MR/H

like MR/H+C1  ≈ C1

this would be nice

f(x)=  [(x^3) - 3(x^2) + 4]/x^2

divide through by x^2

you get

f(x) = x - 3 + 4x^(-2)

use the power rule  f(x) = x^n  f'(x) = n*x(n-1)

f'(x) = 1 - 8*x^(-3)

then factor out x^(-3)

[x^3 - 8]*x^(-3) =  [(x^3)-8]/x^3

1/4(2+Cos[2(a-b)]+Cos[2(a+b)]-2Cos[c]Sin[a]Sin)  <- something seems wrong here

Sin needs a variable.

if a = 0 b= pi/4

you get 1/2

but you might be able to get something smaller than that.

You might try taking partial derivatives of  Cos[2(a-b)]+Cos[2(a+b)] wrt a & b and look for extrema. You could also try to write an excel spread sheet which tries different combinations of a & b and use the goal seek function.

I am in a hurry but I will try to work on it later.

A . (A + 3B +7C) = A.A + 3(A.B) + 7(A.C)

A.B and A.C are given 

A . (A + 3B +7C) = A.A +(3*3) +(7*-1)

A . (A + 3B +7C) = A.A + 2

whats A.A

X.Y = |X|*|Y| * cos(θ)

A is PARALLEL to A there for θ = 0

or

The angle between A and A is 0

cos(0) = 1

A.A = 4

A . (A + 3B +7C) = 4 + 2 =6

hope that helps

edit: previously i said normal