/* Howell - starting with given expression : /$ ∫[∂(θ),0 to 2*π: sin(θ)/(1 - β^2*sin(θ)^2)^(3/2)} /* From "Howell - Background math for Lucas Universal Force, Chapter 4.odt" Recurring integrals from http://integral-table.com /$ ∫[∂(θ),0 to Of: sin(θ)^2) = O/2 - sin(2*O)/4 | from 0 to Of = O ^2/2 - sin(2*O)/4 | from 0 to Of = (Of^2/2 - sin(2*Of)/4) - (0 - 0) /* Take a look at (1 - b^2*sin^2(O))^(-3/2) As a hunch, take the derivative /$ ∂(∂(θ): (1 - β^2*sin(θ)^2)^( - 1/2) = (-1/2)*(1 - β^2*sin(θ)^2)^(-3/2)*∂(∂(θ): (1 - β^2*sin(θ)^2)) = (-1/2)*(1 - β^2*sin(θ)^2)^(-3/2)*(-1)*β^2*2*sin(O)*∂(∂(θ): sin(θ)) = (-1/2)*(-2)*β^2*sin(O)*cos(θ)*(1 - β^2*sin(θ)^2)^(-3/2) = β^2*sin(O)*cos(θ)*(1 - β^2*sin(θ)^2)^(-3/2) /* 27Jun2016 Now look at original integral As a hunch, take sin(O)*(1 - b^2*sin^2(O))^(-1/2) /$ ∂[∂(θ): sin(O)*(1 - β^2*sin(θ)^2)^( - 1/2)] = ∂[∂(θ): sin(O)]*(1 - β^2*sin(θ)^2)^(-1/2) + sin(O)*∂[∂(θ): (1 - β^2*sin(θ)^2)^( - 1/2)] = cos(O) *(1 - β^2*sin(θ)^2)^(-1/2) + sin(O)*[ β^2*sin(O) *cos(θ)*(1 - β^2*sin(θ)^2)^(-3/2) ] = cos(O) *(1 - β^2*sin(θ)^2)^(-1/2) + β^2*sin(O)^2*cos(θ)*(1 - β^2*sin(θ)^2)^(-3/2) = [ cos(O) *(1 - β^2*sin(θ)^2)^1 + β^2*sin(O)^2*cos(θ) ] *(1 - β^2*sin(θ)^2)^(-3/2) = [ cos(O) - cos(O)*β^2*sin(θ)^2)^1 + β^2*sin(O)^2*cos(θ) ] *(1 - β^2*sin(θ)^2)^(-3/2) = cos(O) *[1 - β^2*sin(θ)^2)^1 + β^2*sin(O)^2 ] *(1 - β^2*sin(θ)^2)^(-3/2) = cos(O) *(1 - β^2*sin(θ)^2)^(-3/2) /* Nuts - cos instead of sin (50% chance of wrong, and I did wrong) Now try : /$ ∂[∂(θ): cos(O)*(1 - β^2*sin(θ)^2)^( - 1/2)] = ∂[∂(θ): cos(O)]*(1 - β^2*sin(θ)^2)^(-1/2) + cos(O)*∂[∂(θ): (1 - β^2*sin(θ)^2)^( - 1/2)] = -sin(O) *(1 - β^2*sin(θ)^2)^(-1/2) + cos(O)*[ β^2*sin(O) *cos(θ) *(1 - β^2*sin(θ)^2)^(-3/2) ] = -sin(O) *(1 - β^2*sin(θ)^2)^(-1/2) + β^2*sin(O) *cos(θ)^2*(1 - β^2*sin(θ)^2)^(-3/2) = [ -sin(O) *(1 - β^2*sin(θ)^2)^1 + β^2*sin(O)*cos(θ)^2 ] *(1 - β^2*sin(θ)^2)^(-3/2) = sin(O)*[-1 + β^2*sin(θ)^2) + β^2 *cos(θ)^2 ] *(1 - β^2*sin(θ)^2)^(-3/2) = sin(O)*[-1 + β^2*(sin(θ)^2) + cos(θ)^2) ] *(1 - β^2*sin(θ)^2)^(-3/2) = sin(O)*[-1 + β^2 ] *(1 - β^2*sin(θ)^2)^(-3/2) /* Therefore (NOTE! Lucas specifies dO, 0 to 2*π, but it must be 0 to π ??!!?? /$ ∫[∂(θ),0 to π: sin(θ)/(1 - β^2*sin(θ)^2)^(3/2)} = cos(O) *(1 - β^2*sin(θ)^2)^(-1/2) / (-1 + β^2) | from 0 to π = { cos(π) *(1 - β^2*sin^2(π))^(-1/2) / (-1 + β^2) } - { cos(0) *(1 - β^2*sin^2(0))^(-1/2) / (-1 + β^2) } = { (-1) *(1 - β^2*0 )^(-1/2) / (-1 + β^2) } - { ( 1) *(1 - β^2*0 )^(-1/2) / (-1 + β^2) } = -2 /(-1 + β^2) = 2 / (1 - β^2) /*++++++++++++++++++++++++++++++++++++++ /*add_eqn "Lucas_Typo_or_omission 04_42 Special integral with binomial series /$ (1 - β^2*sin(θ)^2)^(3/2) /$L ∫[∂(φ),0 to 2*π: ∫[∂(θ),0 to π: ET*(1 - λ(v))*r*sin(O)/(1 - β^2*sin(θ)^2)^(3/2)]} = 4*π*Q*(1 - λ(v))/(1 - β^2) ∫[∂(θ),0 to 2*π: sin(θ)/(1 - β^2*sin(θ)^2)^(3/2)) = 2/(1 - β^2) /* and /$ E0(r) = q/r^2 /* so /$L λ(v) = β^2 /$H ∫[∂(φ),0 to 2*π: ∫[∂(θ),0 to π: E0*(1 - λ(v))*r*sin(O)/(1 - β^2*sin(θ)^2)^(3/2)]*r} = 4*π*Q*(1 - λ(v))/(1 - β^2) ∫[∂(θ),0 to 2*π: sin(θ)/(1 - β^2*sin(θ)^2)^(3/2)) = 2/(1 - β^2) /* and /$ E0(r) = q/r^2 /* so /$ λ(v) = β^2 /* OK - easy, but Lucas uses wrong 2*π rather than π upper limit on sinO/(1 - b^2*sin^2(O))^(3/2) integral, and uses ET rather than E0, and is missing an r! HOWEVER : my 4-37 is missing the lambda term - so my earlier resilts dont work with this (maybe some other twisted argument will do for me?).