2nd PUC Mathematics Series 2

11. If f(x) = 3x+2/5x−3 then (fof)(x) is

12. The number of binary operations that can be defined on a set of 2 elements is

13. Let * be a binary operation on Q, defined by a * b = 3ab/5 is

14. Let * be a binary operation on set Q of rational numbers defined as a * b = ab/5. Write the identity for *.

15. For binary operation * defind on R – {1} such that a * b = a/b+1 is

16. he binary operation * defind on set R, given by a * b = a+b/2 for all a,b ∈ R is

17. Let A = N × N and * be the binary operation on A defined by (a, b) * (c, d) = (a + c, b + d). Then * is

18. Find the identity element in the set I⁺ of all positive integers defined by a * b = a + b for all a, b ∈ I⁺.

19. Let * be a binary operation on set Q – {1} defind by a * b = a + b – ab : a, b ∈ Q – {1}. Then * is

20. The binary operation * defined on N by a * b = a + b + ab for all a, b ∈ N is