Problem 5. Which of the fottowing are true and which are false? 1. {{@}} U (0 = {9, {0}} 2- {{@}} U {9} = {0: {9}} 3- {9, {0}} {{9}}, {{0}}} = {9} 4- {9, {0}} {{9}}, {{0}}} = {{9}} 5. For sets A,B, and 0, AU (B 0) = (AUB) (AUG). Problem 6. Consider the function g : Z > Q dened by g(n) = 1/(n2 + 2). Is 9 injective? Is g suijective? What is the image of g? Sketch a graph of g. Problem 7. Let g : R2 > R be dened by g(3:,y) = m + y. Is 9 surjective? Is 9 injective? Problem 8. A function f : R > R is said to be odd if Va: 6 1R, f(a:) f,g : R > R are odd functions. Is f o g and odd function? Problem 9. A function f : R > R is said to be even if Va: 6 1R, f(a:) = f(a:). Prove or disprove the following f (3:) Suppose Vf:R>R,3g:R>Rs.t. (f is odd)=>(fogiseven)