بسم هللا الرحمن الرحيم Kingdom of Saudi Arabia الـمـمـلكـة الـعـربـيـة الـسـعـوديـة وزارة الـتـعـلـيـم الـعـالـي جـامـعـة الـمـجـمـعـة كلية العلوم بالزلفي Ministry of Higher Education Majmaah University College Of Sciences in Alzulfi non -:تاريخ االمتحان السادس-:المستوى MAT 373-Z -:رقم ورمز المادة مقدمة في التو بولوجي-:اسم المادة Answer the Following Questions: Q1) a) Define a compact space and prove if ( X , ) is T2 space and F is compact set In X then F is closed b) Prove: A topological space ( X , ) is T1 space iff x X , and then x is a closed set c) Define T0 , hereditary property and prove T0 space is a hereditary property Q2) a) Define T2 space and prove that every discrete space is not compact and indiscrete space is compact b) Consider the topology 𝜏 = {𝑋, ∅, {1}, {1,4}, {1,3,4}} on 𝑋 = {1,2,3,4} and let 𝐴 = {2,3,4}. Find 𝐴° , 𝐴 , 𝑏(𝐴), 𝐴́ c) Define homeomorphism, topological property and prove that the density is a topological property Q3) a) correct the following statements (if it’s incorrect) (any statement mark) 1) Let 𝑋 = {𝑎, 𝑏, 𝑐}, 𝜏 = {𝑋, ∅, {𝑎}, {𝑏}, {𝑎, 𝑐}} . Then 𝜏 is a topology on 𝑋 2) Let 𝑋 = {1,2,3}, 𝜏 = {𝑋, ∅, {1}, {1,2}} is a topology on 𝑋, if 𝐴 = {2,3}. Then 𝐴° = {2,3} 3) A topological space (𝑋, 𝜏) is 𝑇1 -space if ∀𝑥, 𝑦 ∈ 𝑋, ∃𝑢, 𝑣 ∈ 𝜏 𝑠. 𝑡. , 𝑥 ∈ 𝑢, 𝑦 ∈ 𝑣 4) A topological space (𝑋, 𝜏) is compact space if every open cover has a finite sub cover 5) Let 𝑋 = {𝛼, 𝛽, 𝛾, 𝜀, 𝜖, 𝜃}, 𝜏 = {𝑋, ∅, {𝛽}, {𝛽, 𝜀}} is a topology on 𝑋. Then (𝑋, 𝜏) is connected space 6) If ( X , ) is a topological space, A X then A' A is open set 7) If ( X , ) is open sets a topological space, A X then A open sets, A closed sets, A' A, b( A) A A 8) In usual topology ( R, U ) , (0,1) ' [0,1) 9) If ( X , ) is a topological space, A X then A { : } is topology on A 1 بسم هللا الرحمن الرحيم Kingdom of Saudi Arabia الـمـمـلكـة الـعـربـيـة الـسـعـوديـة وزارة الـتـعـلـيـم الـعـالـي جـامـعـة الـمـجـمـعـة كلية العلوم بالزلفي Ministry of Higher Education Majmaah University College Of Sciences in Alzulfi non -:تاريخ االمتحان السادس-:المستوى MAT 373-Z -:رقم ورمز المادة مقدمة في التو بولوجي-:اسم المادة 10) If ( X , ) is a topological space, P X then is a neighborhood of a point P if G s.t. P G X 11) If is a base of a topological space ( X , ) , then Bi , i Bi 12) If ( X , I ) is indiscrete topological space, ( X , D ) is a discrete topological space, then f : ( X , I ) ( X , D) is continuous function 𝑏) Define a complete lattice, linear order and prove A subset A of a topological space X is closed iff A contains each of its accumulation point c) Define continuity and Prove: A function f : X Y is continuous if and only if the inverse image of every closed subsets of Y is closed subsets of X 2