7.35 is nothing more than a definition of spherical coordinates. ⎧ x = r sinθ cosϕ ⎪ ⎨ y = r sinθ sinϕ ⎪ ⎩ z = r cosθ Some differential forms may come in handy. ∂/∂θ: ⎧ ∂x = r cosϕ cosθ ∂θ ⎪ ⎨ ∂y = r sinϕ cosθ ∂θ ⎪ ⎩ ∂z = - r sinθ ∂θ ∂/∂ϕ: ⎧ ∂x = - r sinθ sinϕ ∂ϕ ⎪ ⎨ ∂y = r sinθ cosϕ ∂ϕ ⎪ ⎩ ∂z = 0 ∂ϕ 7.47 is the set of algebraic conditions expressed by the vector definition 𝐋 = 𝐫 × 𝐩. ⎧ L̂𝓍 = yp𝓏 - zp𝓎 = -ιħ (y ∂͟_ - z ∂͟_ ) ⎪ ∂z ∂y ⎪ ⎨ L̂𝓎 = zp𝓍 - xp𝓏 = -ιħ (z ∂͟_ - x ∂͟_ ) ⎪ ∂x ∂z ⎪ ⎪ L̂𝓏 = xp𝓎 - yp𝓍 = -ιħ (x ∂͟_ - y ∂͟_ ) ⎩ ∂y ∂x Substituting 7.35 into 7.47, ⎧ L̂𝓍 = -ιħ (r sinθ sinϕ ∂͟_ - r cosθ ∂͟_ ) ⎪ ∂z ∂y ⎪ ⎨ L̂𝓎 = -ιħ (r cosθ ∂͟_ - r sinθ cosϕ ∂͟_ ) ⎪ ∂x ∂z ⎪ ⎪ L̂𝓏 = -ιħ (r sinθ cosϕ ∂͟_ - r sinθ sinϕ ∂͟_ ) ⎩ ∂y ∂x Geometry is shown on the attached notes page. For L̂𝓍: ∂͟z͟ = -r sinθ ∂θ ∂͟y͟ = r sinθ cosϕ ∂ϕ L̂𝓍 = -ιħ ( r sinθ sinϕ ∂͟θ͟ ∂͟_ - r cosθ ∂͟ϕ͟ ∂͟_ ) ∂θ ∂z ∂ϕ ∂y L̂𝓍 = ιħ ( -r sinθ sinϕ ∂͟θ͟ ∂͟_ + r cosθ ∂͟ϕ͟ ∂͟_ ) ∂z ∂θ ∂y ∂ϕ L̂𝓍 = ιħ ( −͟r͟ s͟i͟n͟θ͟ sinϕ ∂͟_ + c͟o͟s͟θ͟ ∂͟_ ) -r sinθ ∂θ sinθ cosϕ ∂ϕ L̂𝓍 = ιħ ( sinϕ ∂͟_ + c͟o͟t͟θ͟ ∂͟_ ) ∂θ cosϕ ∂ϕ For L̂𝓎: ∂x = r cosϕ cosθ ∂θ ∂z = 0 ∂ϕ L̂𝓎 = -ιħ (r cosθ ∂͟_ - r sinθ cosϕ ∂͟_ ) ∂x ∂z L̂𝓎 = ιħ (-r cosθ ∂͟θ͟ ∂͟_ + r sinθ cosϕ ∂͟ϕ͟ ∂͟_ ) ∂θ ∂x ∂ϕ ∂z L̂𝓎 = ιħ (-r cosθ ∂͟θ͟ ∂͟_ + r sinθ cosϕ ∂͟ϕ͟ ∂͟_ ) ∂x ∂θ ∂z ∂ϕ L̂𝓎 = ιħ (- _͟1͟ cosθ ∂͟_ + r sinθ cosϕ 0 ∂͟_ ) cosϕ cosθ ∂θ ∂ϕ L̂𝓎 = ιħ (- _͟1͟ ∂͟_ ) cosϕ ∂θ L̂𝓎 = -ιħ _͟1͟ ∂͟_ cosϕ ∂θ For L̂𝓏: ∂x = -r sinθ sinϕ ∂ϕ ∂y = r sinθ cosϕ ∂ϕ L̂𝓏 = -ιħ (r sinθ cosϕ ∂͟͟ϕ͟ ∂͟_ - r sinθ sinϕ ∂͟͟ϕ͟ ∂͟_ ) ∂ϕ ∂y ∂ϕ ∂x L̂𝓏 = -ιħ (r͟ s͟i͟n͟θ͟ c͟o͟s͟ϕ͟ ∂͟_ + r͟ s͟i͟n͟θ͟ s͟i͟n͟ϕ͟ ∂͟_ ) r sinθ cosϕ ∂ϕ r sinθ sinϕ ∂ϕ L̂𝓏 = -ιħ ∂͟_ ( 1 + 1 ) ∂ϕ L̂𝓏 = -2ιħ ∂͟_ ∂ϕ So, according to my calculus, the final solutions should be the set ⎧ L̂𝓍 = ιħ ( sinϕ ∂͟_ + c͟o͟t͟θ͟ ∂͟_ ) ⎪ ∂θ cosϕ ∂ϕ ⎪ ⎨ L̂𝓎 = -ιħ _͟1͟ ∂͟_ ⎪ cosϕ ∂θ ⎪ ⎪ L̂𝓏 = -2ιħ ∂͟_ ⎩ ∂ϕ The spherical representation, i.e. ending place, is the set ⎧ L̂𝓍 = ιħ (sinϕ ∂͟_ + cosϕ cotθ ∂͟_ ) ⎪ ∂θ ∂ϕ ⎪ ⎨ L̂𝓎 = ιħ (-cosϕ ∂͟_ + sinϕ cotθ ∂͟_ ) ⎪ ∂θ ∂ϕ ⎪ ⎪ L̂𝓏 = -ιħ ∂͟_ ⎩ ∂ϕ My set DOES NOT match this. I must be going about this the wrong way. I have to give it more thought. Perhaps a purely geometric approach will improve my answers: I'll try that over the weekend.