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SET, MAPPING, BINARY OPERATION, GROUPS

Set: A well define collection of distinct objects is called set. Usually, the objects are called elements of the set Null set or Empty set or Valid set:  A set which has no member (or element) is called a null set. Null set is denoted by Φ or {  }. Sub-sets: If every elements of a set A is an element of the set B, then A is said to be subset of B; symbolically we write A ⊆ B or B⊇ A. If A ⊆ B and there is an element in B which is not in A, then A is said to be proper subset  of B denoted by  A ⊂ B If A is not a subset of B, we write A ⊄ B because b ∈ A but b ∉ B NOTE: i) If A ⊂B then x  ∈ A => x  ∈ B ii) Every set is subset of itself i.e., A  ⊂ A iii) If  A ⊂B, then an element not in B is not in A. iv) Null set is subset of every set. (Follow from (iii)) Equality of two sets: Two sets A and B are said to be equal if A ⊆ B and B  ⊆ A; we write A= B. Universal sets: In a context if every set is subset of another set, say U then U is called...

REVISION - XII

DETERMINANT  1) If two rows or two columns of a determinant are identical then the value of the determinant is a) 0 b) 2 c) -1 d) 1 2) If D= 0     a    b              -a     0    c              -b    -c    0 then D is  a) 0 b) 1 c) a d) b 3) a+b    a+2b    a+3b     a+2b  a+3b    a+4b= 0     a+4b  a+5b     a+6b 4 ) 1+ a      1        1       1       1+ b     1        1         1      1+ c = abc(1/a + 1/b + 1/c) 5) loga       p      1     logb       q       1 = 0 (a,b,c> 0)     logc       r     ...