Discrete Structures : One-to-one, Onto and Range

Let f(x) = x^2 + x - 12. Consider f as a function from the reals to the reals. Is f one-to-one? Is f onto? What is the range of f?

Discrete Structures : Onto and One-to-one

Prove or disprove (find a counterexample) : If A C B and f : A --> B is an onto function (the range of f is all of B), then f is one-to-one and A =B. Please see the attached file for the fully formatted problem.

Discrete Structures : Reflexive, Symmetric or Transitive Relation

Let S ne the set of all strings of a's and b's. Let R be the relation on S defined by... x and y begin with different symbols. Determine, and prove your answers, whether or not R is reflexive, symmetric or transitive. Please see the attached file for the fully formatted problems.

Discrete Structures : Congruences

Construct addition and multiplication tables for arithmetic modulo 11. For example, 7 + 8 mod 11 is 4 and 7*8 mod 11 is 1 so the entry in row 7, column 8 would be 4 for the addition table and 1 for the multiplication table. Use your tables to solve each of the following congruences: a. 3x+2≡8 (mod11) b. 3x-5≡2 (mod11) c. 2x2 + x + 8≡0 (mod 11)

Discrete Structures : Reflexive, Symmetric or Transitive Relations

Let S be the set of all strings of a’s and b’s. Let R be the relation on S defined by....x and y begin with different symbols. Determine and prove your answers, whether or not R is reflexive, symmetric or transitive.