Finite difference discretization of Elliptic equations: ID Problem ecture 2 and 3￾✂✁☎✄✆✁✞✝✠✟☛✡☞✁✍✌✎✟✑✏✒✟✓✄✕✔✑✟☛✡☞✁☎✖✗✔✑✏✒✟✘✝✗✁☎✙✛✚✜✝✗✁✣✢✤✄ ✢✦✥★✧✪✩☎✩☎✁☎✫✬✝✠✁✣✔✭✧✯✮✱✰✲✚✜✝✠✁✣✢✤✄✆✖✛✳✵✴✜✡ ✶✷✏✒✢✤✸✕✩✣✟✓✹ ✺✻✟✑✔✼✝✠✰✕✏✒✟✓✖✾✽✿✚❀✄❂❁❄❃