# Weekly Report 2.2 [toc] ## Method of separable variables ![](https://i.imgur.com/HQiyeE1.png) ![](https://i.imgur.com/BSGazYC.png) 然後討論 lamda>=<0 的情況 :::spoiler lamda>0 ![](https://i.imgur.com/Ma2hNNo.png) ::: :::spoiler lamda=0 ![](https://i.imgur.com/EO98DuD.png) ::: ## Solutions for 2D Laplace's equations Cartesian Coordinate System ![](https://i.imgur.com/HQiyeE1.png) ![](https://i.imgur.com/0C16UmQ.png) beta<0,和beta>0,式子長的一樣 ![](https://i.imgur.com/EUAJ5iO.png) 所以 V 有 2X2 種型態 或是 ![](https://i.imgur.com/72bsNqZ.png) 所以 V 有 2X2 種型態 所以 ![](https://i.imgur.com/dHBNEuZ.png) ![](https://i.imgur.com/IMmITjt.png) 注意:要注意 possible complete solutions 不要寫成 invalid solutions ## Invalid Solutions in 2D Cartesian Coordinate :::spoiler Picture ![](https://i.imgur.com/NJjoBGL.png) ::: ![](https://i.imgur.com/aWnQBBd.png) 因為前面,所以現在我們知道 ![](https://i.imgur.com/TQhp2cz.png) 然而 ![](https://i.imgur.com/eqox32c.png) ### Basic Problem: three boundary conditions :::danger 每一種的推導過程相當類似,考試前強烈建議自己重新推推看。boundary conditions 可以當作特殊案例,當特殊案例常出現時,我們就可以幫它當作一種題型,要熟悉到可以看圖就可以反射想出結果。 ::: ![](https://i.imgur.com/rWwquod.png) :::spoiler ![](https://i.imgur.com/dAg2FcE.png) ::: ![](https://i.imgur.com/P1AL7zc.png) :::spoiler ![](https://i.imgur.com/DG5icjR.png) ::: ![](https://i.imgur.com/34mr5IP.png) :::spoiler ![](https://i.imgur.com/BLAvJD9.png) ::: ![](https://i.imgur.com/X8ZONJJ.png) :::spoiler ![](https://i.imgur.com/e9eZQdd.png) ::: ### More than one non-zero boundary conditions :::danger 這段同上,考試前推一下。要熟悉到可以看圖想結果。 ::: ![](https://i.imgur.com/hbZGZCq.png) :::spoiler 1. Detail ![](https://i.imgur.com/MvWAmiA.png) ::: ![](https://i.imgur.com/6S6jqDx.png) :::spoiler 2. Detail ![](https://i.imgur.com/1QLCSue.png) ::: ### Hybrid boundary conditions ![](https://i.imgur.com/ruTPxJQ.png) :::spoiler ![](https://i.imgur.com/9tJ52dg.png) ::: ### Division of Problem Domains ![](https://i.imgur.com/Ysnsq2v.png) :::spoiler ![](https://i.imgur.com/aT5CMCm.png) ::: ## Solving Poisson’s Equations :::danger 這段同上,考試前推一下。要熟悉到可以看圖想結果。 ::: ![](https://i.imgur.com/2EdjrSa.png) :::spoiler ![](https://i.imgur.com/2DDOwBb.png) ::: ![](https://i.imgur.com/2Rcq1i1.png) :::spoiler ![](https://i.imgur.com/FzD2YxR.png) ::: ![](https://i.imgur.com/ItH3tiZ.png) :::spoiler ![](https://i.imgur.com/9wtHXWW.png) ::: ### Check of boundary conditions :::danger 這段同上,考試前推一下。要熟悉到可以看圖想結果。 ::: ![](https://i.imgur.com/kPSQ8nz.png) :::spoiler Boundary conditions for the Poisson solution ![](https://i.imgur.com/n4rZdLX.png) ::: ![](https://i.imgur.com/2jnr4Id.png) :::spoiler ![](https://i.imgur.com/HRQE4Xf.png) ::: ![](https://i.imgur.com/WMFWHXS.png) :::spoiler ![](https://i.imgur.com/frfbqY1.png) ::: ## Solution to the Poisson Equation with Homogeneous Boundary Conditions ![](https://i.imgur.com/7mCbaxo.png) ![](https://i.imgur.com/rZKLBM2.png) ![](https://i.imgur.com/q8BSFTZ.png) ### Solution to the Poisson Equation with Homogeneous Boundary Conditions :::danger 這段應該要和 Laplace Equation 做比較 ::: ![](https://i.imgur.com/dOYBtqY.png) ![](https://i.imgur.com/Y0rPh0p.png) ### Solution to the Laplace Equation with Non-Homogeneous Boundary Conditions :::danger 這段應該要和 Poisson Equation 做比較 ::: ![](https://i.imgur.com/F0pRoHM.png) ![](https://i.imgur.com/yBz2JjQ.png) ### Complete solution ![](https://i.imgur.com/aSnZBHm.png) # 心得 這段感覺是過去的總和,不過相對沒有新鮮感,主要是數學的推導,很多的推導過程相當類似,考試前強烈建議自己重新推推看,而且可以把類似的部分拿出來做比較,透過對照找出不同之處可以讓我們對於該部分的印象特別加深。 對我來說 boundary conditions 可以把她當作特殊案例,當特殊案例常出現時,我們就可以幫它當作一種題型,自己做歸納,或是找出規律、記憶點來方便自己熟悉題型,直到可以看圖就可以反射想出結果。