07/10/2024
৯ম-১০ম শ্রেণী # #
প্রাত্যহিক জীবনে সেট -
প্রথম অধ্যায় (অনুশীলনী অংশ)::
৪। যদি U = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, A = {1, 3, 5, 7}, B ={0, 2, 4, 6} এবং C = {3, 4, 5, 6, 7} হয়, তবে নিম্নলিখিত ক্ষেত্রে সত্যতা যাচাই করো :
ক) (A ∪ B)c = Ac ∩ Bc
সমাধানঃ
দেওয়া আছে,
U = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, A = {1, 3, 5, 7}, B ={0, 2, 4, 6} এবং C = {3, 4, 5, 6, 7}
এখন,
বামপক্ষ
= (A ∪ B)c
= U – (A ∪ B)
= U – ({1, 3, 5, 7} ∪ {0, 2, 4, 6})
= U – {0,1,2,3,4,5,6,7}
= {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} - {0,1,2,3,4,5,6,7}
= {8,9}
ডানপক্ষ
= Ac ∩ Bc
= (U –A) ∩ (U-B)
= ({0, 1, 2, 3, 4, 5, 6, 7, 8, 9} – {1, 3, 5, 7}) ∩ ({0, 1, 2, 3, 4, 5, 6, 7, 8, 9}-{0, 2, 4, 6})
= {0,2,4,6,8,9} ∩ {1,3,5,7,8,9}
= {8,9}
∴ বামপক্ষ = ডানপক্ষ [সত্যতা যাচাই করা হলো]
খ) (B ∩ C)c = Bc ∪ Cc
সমাধানঃ
দেওয়া আছে,
U = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, A = {1, 3, 5, 7}, B = {0, 2, 4, 6} এবং C = {3, 4, 5, 6, 7}
বামপক্ষ
= (B ∩ C)c
= U – (B ∩ C)
= U - ({0, 2, 4, 6} ∩ {3, 4, 5, 6, 7})
= U – {4,6}
= {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} - {4,6}
= {0,1,2,3,5,7,8,9}
ডানপক্ষ
= Bc ∪ Cc
= (U-B) ∪ (U-C)
= ({0, 1, 2, 3, 4, 5, 6, 7, 8, 9}-{0, 2, 4, 6}) ∪ ({0, 1, 2, 3, 4, 5, 6, 7, 8, 9}-{3, 4, 5, 6, 7})
= {1,3,5,7,8,9} ∪ {0,1,2,8,9}
= {0,1,2,3,5,7,8,9}
∴ বামপক্ষ = ডানপক্ষ [সত্যতা যাচাই করা হলো]
গ) (A ∪ B) ∩ C = (A ∩ C) ∪ (B ∩ C)
সমাধানঃ
দেওয়া আছে,
A = {1, 3, 5, 7}, B = {0, 2, 4, 6} এবং C = {3, 4, 5, 6, 7}
বামপক্ষ
= (A ∪ B) ∩ C
= ({1, 3, 5, 7} ∪ {0, 2, 4, 6}) ∩ {3, 4, 5, 6, 7}
= {0,1,2,3,4,5,6,7} ∩ {3, 4, 5, 6, 7}
= {3,4,5,6,7}
ডানপক্ষ
= (A ∩ C) ∪ (B ∩ C)
= ({1, 3, 5, 7} ∩ {3, 4, 5, 6, 7}) ∪ ({0, 2, 4, 6} ∩ {3, 4, 5, 6, 7})
= {3,5,7} ∪ {4,6}
= {3,4,5,6,7}
∴ বামপক্ষ = ডানপক্ষ [সত্যতা যাচাই করা হলো]
ঘ) (A ∩ B) ∪ C = (A ∪ C) ∩ (B ∪ C)
সমাধানঃ
দেওয়া আছে,
A = {1, 3, 5, 7}, B = {0, 2, 4, 6} এবং C = {3, 4, 5, 6, 7}
বামপক্ষ
= (A ∩ B) ∪ C
= ({1, 3, 5, 7} ∩ {0, 2, 4, 6}) ∪ {3, 4, 5, 6, 7}
= ∅ ∪ {3, 4, 5, 6, 7}
= {3,4,5,6,7}
ডানপক্ষ
= (A ∪ C) ∩ (B ∪ C)
= ({1, 3, 5, 7} ∪ {3, 4, 5, 6, 7}) ∩ ({0, 2, 4, 6} ∪ {3, 4, 5, 6, 7})
= {1,3,4,5,6,7} ∩ {0,2,3,4,5,6,7}
= {3,4,5,6,7}
∴ বামপক্ষ = ডানপক্ষ [সত্যতা যাচাই করা হলো]